“Miracles” in Islamic theological terms are acts that surpass normal limits that challenge others to do the same and are in accordance with the claims of the person performing them. What is meant by surpassing normal limits is that it seems contrary to the laws of nature.
Of course, when it is said that miracles surpass normal limits, not having a cause or negating the law of causality isn't intended; what is meant is that despite these phenomena having their own natural causes, these causes are unknown and inaccessible to the people. What is meant by ‘challenge’ is that the prophet performing the miracle challenges those rejecting his call and his miracle to do something similar. Miracles are done by the prophets themselves and with the permission of Allah, meaning that the miracle originates from the never ending power of Allah (swt), thus always making it prevalent. When it comes to miracles, there is no need of learning or practice, and as a result, it is unconditional and can take place no matter what. Prophets’ miracles aren't done out of amusement, etc., but are done with the intention of guiding humanity; this is what sets miracles apart from other uncommon phenomena such as the answering of prayers, etc., and magic and sorcery.
In such phenomena, there is no sign of challenges or guidance or claims of prophethood. No natural sources can be identified in magic and sorcery, as well as other acts which are performed by ascetics. Even when a natural source can be identified as the means by which these acts are performed, still, the intention behind such acts is never divine. In addition to this, the such things are attained through practice and learning, and such a person can only do a certain thing and not anything he is asked to; add to that the fact that since such powers originate from man and are thus limited, what such people do can be countered and overcome by supernatural powers.
As to proving miracles: Miracles can be divided into two sections: sometimes miracles will be certain acts, and sometimes in words. Generally, miracles manifested through actions are of a nature whereby they do not remain with the passing of time, even though we do have some exceptions in miracles performed by the Prophet of Islam (s).
The proof of such miracles for those who were not present during their manifestation can be found in the reports narrated by those who were present. The word based miracle of the Prophet (s) is the Quran that is with us today; in many instances, the Quran has challenged the ones who rejected it with the creation of a similar book, which they were unable to respond to.
The miracle of the Quran is not limited to a specific field such as its eloquence and fluidity; the Quran is superior when it is viewed from any angle and this comprises its miraculous nature. If one looks at the Quran from the perspective of science, or its utter absence of contradiction, its news of the unseen, and various other issues, its miraculous nature is clearly evident.
When defining the term “Miracle”, Islamic scholars have said:
“Miracles” are acts that surpass normal limits that challenge others to do the same and are in accordance with the claims of the person performing them. What is meant by surpassing normal limits is that it seems contrary to the laws of nature.
Of course, when it is said that miracles surpass normal limits, not having a cause or negating the law of causality isn't intended, because causality is something both the intellect and Quran support. The law of causation and that of the supernatural are both accepted by the Quran. While this is the case, the Quran also teaches that all causation is in the hands of God and that material causes are not somehow independent; the real source of causation is God. Along these same lines, the Prophets (a) have been one factor in the manifestation of miracles and the Lord within them and God’s chosen ones and the believers, transcends all outer causes and overcomes all of them.
To sum it up, like other normal phenomena, miracles and other supernatural phenomena are dependent on the rules of causation. In addition, both of these phenomena (miracles and normal phenomena) all possess internal esoteric causes, these internal causes differing from what we perceive to be causes of phenomena. In normal phenomena, normal outer causes are actually in conjunction with inner esoteric ones (which are the true causes of things), which in turn are in conjunction with the will and decree of God. In some cases, inner causes do not correlate to normal causes and as a result, those normal causes lose their causative effect, thus, normal occurrences which should take place do not take place and this is just simply because God has not willed it so. On the other hand, supernatural occurrences rely on a chain of natural causation not understood and easily comprehended by the average person. In spite of people not understanding the causes of supernatural phenomenon, these still are dependent on the permission of God (which as was mentioned, is the real cause of everything) and it is completely incorrect to see them as outside the scope of His power.
One of the other conditions of miracles is that they are accompanied with a challenge by their doer to match them (in Islamic terms, this is referred to as tahaddi). Meaning that the prophet performing the miracle challenges everyone, especially the disbelievers and deniers, to do as he does if they see what he has done as something that doesn’t confirm the prophet’s claim of being messenger of God.
In other words, the miracle is proof and a divine sign that proves ones claim of being sent on a divine mission, and that is why it has specific conditions and is accompanied by a challenge to match it.
Another of the conditions of a miracle is that if an individual claims to be a prophet (a) and his claim of a miracle involves (for example) curing the blind to see, then he must actually be able to do such an act or else the truth of his statement will not be accepted.
Therefore, a miracle is an extraordinary act or event, and although sorcery, soothersaying and answering of supplications are all extraordinary acts as well, they cannot stand against the miracle and its cause and are defeated by it. What makes a miracle a miracle, is that its natural and yet, unordinary causes are never defeated and are always the victor. On the other hand, magic and other supernatural acts do not originate from a divine source, nor do they originate from a natural (physical or ordinary) source. Such acts tend to involve trickery over the mind and imagination, and in the case that they originate from a natural source, they serve the interests of evil and are usually intertwined with superstition and ignorance. So, it can be concluded that there is also another difference between extraordinary acts and miracles, and that is in the aim behind each one. The prophets (a) manifested miracles in order to guide humanity, not in for entertainment, etc.
From another angle, miracles do not require special training; this is contrary to ascetics who learn how to perform supernatural acts through long periods of training and practice. In addition, these ascetics are not able to perform any act which they wish; they are limited by the amount of their training and practice. Such a thing is due to the fact that prophets (a) rely on the unlimited power of the divine for their performance of miracles, while ascetics must rely on the limited power of humans in order to perform their miracles.
Miracles are different from other extraordinary acts in the respect that they are designed to guide humanity, and through their manifestation, the truth of a prophets (a) prophethood is proven. In addition, a prophet (a) is able to manifest his miracles at any time with the permission of God. As for the supplication of individuals who are close to God (the result of which are extraordinary acts called Kiraamah), this is different than a miracle in that if it is not granted, the guidance of the people will not be affected.
In other words, a Kiraamat is a supernatural act from a perfect or almost perfect human being which generally comes from his spiritual power and holiness. Furthermore, it is not designed to prove anything divine necessarily. A miracle proves an individual is rightly guided, but a Kiraamat does not prove such a thing.
In any case, a miracle is particular only to the prophets (a) and if an individual claims to be a prophet, then their miracles or lack thereof will be the truth of what they claim. The reason being that it is intellectually unacceptable for a liar to be able to perform a miracle, and if he doesn’t claim to be a prophet, then he won't be considered a prophet, because in essence, the miracle does not imply prophethood, what it attests to first and foremost, is the truth of the claim of its performer. Now if the performer claims prophethood, then the miracle will support his claim and prove his prophethood.
The prophets (a) are also able to manifest miracles even before their mission of prophethood, but this is considered as preparing the people for receiving the message and not as a proof of their message (which they have not spoken of yet). This is referred to as Irhaas.
Indeed, miracles are only manifested after the commencement of the prophetic mission and are accompanied by challenge. If any extraordinary phenomenon is exhibited from the prophets (a) before this commencement, then this is considered as a Kiraamat and not as a miracle. This is the case even though all the extraordinary phenomenon exhibited by the prophets (a) and imams (a) are considered to be miracles in the common view of the people.
Still, proving an event as a miracle depends on two issues. The first issue is the various divisions of the miracles of the prophet, while the second are the various miraculous aspects of the Quran. The miracles are further divided into two sections: namely those related to words and those related to actions and events.
The action based miracles include: controlling physical factors through Wilayat Takwini with the permission of God such as the splitting of the moon and splitting of the tree by the Prophet of Islam (s), splitting the ground in the story of Qarun, splitting the sea in the story of Pharoah and Prophet Moses (a), splitting the mountain in the story of Prophet Saalih (a), raising the dead and healing the blind by Prophet Jesus (a), and tearing off the doors of the Khaybar fortress by Imam Ali (a).
Word based miracles include: the words of God, his Prophet (s), and the Imams (a) which include deep fountains of knowledge and reality. Action based miracles pertain to a particular place and time and they are designed for the masses, since they are more concerned with the perceptible realities. On the other hand, word based miracles are not limited to a particular time or place and they remain for all times and are directed more towards a specific group of people.
One of the action based miracles of the Prophet of Islam (s) was his knowledge of the Qiblah (which still exists) without any astronomical tools or guidelines. He simply stood in the direction of the Ka’bah (while in Medina) and said: محرابى على الميزاب (my mihrab is facing the spout of the Ka’bah).
Proving action based miracles requires researching various traditions which have narrated these events. If these traditions are reliable from the perspective of their chains of narration and context, then the events are also considered accurate. If this is not the case, then that event falls under doubt, even if the possibility of its occurrence still remains. The miracles narrated in the Holy Quran are also accepted without any doubt, as well as the action based miracles which are still present.
The Miracle of the Quran: the greatest word based miracle is that of the Quran. In addition, there is no doubt by anyone that the Quran was never tampered with or altered in any way. A question may remain as to how the Quran is such a great miracle. In order to answer this question we must first research the Quran from various angles in order to prove that it is the word of God.
The Quran is miraculous in many various ways and we will mention some of these below:
1- It is a miracle in respect to its eloquence (Balaaghat) and clear language (Fasaahat).
2- It is a miracle due to its lack of contradiction in the various issues it has spoken about. It is for this reason that Imam Ali (a) has said: “Parts of the Quran speak the message of other parts, and some parts are proof [of the veracity] of others.”
3- It is a miracle in the news it gives of the unseen.
4- It is a miracle in respect to who it was revealed to.
5- It is a miracle in respect to the knowledge which it contains…
The Quran proves its miraculous nature through the following way: Imagine an individual who was uneducated and was furthermore raised in an environment which was bereft of morals, knowledge, and civilization. Can such an individual be expected to gain detailed knowledge about various issues which even educated people would find impossible to know? Can he furthermore bring forth a detailed system of life which includes highly detailed political, economic, social, and religious rules for people to live by? Not only did the Prophet (s) do such a thing, but his system of life (the religion of Islam) was so wondrous that all the men of knowledge, the kings, and anyone who came across it was struck in wonder by what he or she saw. This religion even includes extreme details which are not ordinarily thought of, both during modern times and particularly during that time period.
Both the words of the Quran are miraculous, as well as the meaning of its words. To say this in another way, the Quran is both beautiful in its outer form, as well as its inner form. Up to modern times there has been no one who has been able to duplicate the Quran, not even a small chapter such as that of Kawthar.
On a final note, it is important to mention that the Quran has challenged everyone in an absolute manner where it has stated that if anyone is able to, then they should bring forward a similar book. It has not stated that if people are able to, then they should bring forward a book with equal eloquence and teachings as the Quran and this gives the understanding that the Quran is a superior compilation in every respect possible and this is one of its miracles. This challenge extends to every individual in each and every time period possible. If it occurs that there is someone who isn't convinced that the Quran is a miraculous book, in order that its miraculousness is proven to him, he can refer to the experts and those of deep understanding in this regard, those who have dedicated their lives to understanding the teachings of the Quran and believe it to be an ocean of knowledge of which they have only understood a drop of.
 See: Kashf al-Murad fi Sharh Tajrid al-I’tiqad, Allamah Hilli along with the notes and correction of Ayatullah HasanZadeh Amoli, pp. 350-353, and Ayatullah HasanZadeh Amoli’s notes on Kashf al-Murad, p. 595.
Rahbarane Bozorg va Mas’uliyyathaye Bozorgtar, pp. 119-153; Moqaddame’i bar Jahan Biniye Islami, Shahid Mutahhari, Association of Seminary Teachers Press, 1362 (solar), pp. 179-208; Al-Mizan, vol. 1, pp. 58-90 and Farsi translation of Al-Mizan, vol. 1, pp. 93-140; Ensane Kamil az Didgahe Nahjul-Balaghah, pp. 8-21; Tarjomeh va Sharhe Isharate Ibn Sina, Dr. Malekshahi, pp. 466-491; Shawahid al-Rububiyyah, Mulla Sadra along with the notes of the late Sabzwari and also notes and corrections and an introduction by Jalal Ashtiyani, second edition, pp. 340-349; Faslun fi Usul al-Mu’jizaat wa Khawariq al-Adaat, Mabda’ wa Ma’aad, Mulla Sadra, translated by Ahmad ibn Muhammad al-Husayni Ardekani with the efforts of Abdullah Nouri, pp. 538-549.
 Talaq:3; Hijr:21; Qamar:49.
 A’raf:54; Baqarah:284; Hadid:5; Nisa’:80; Aal Imran:26; Taha:50; Baqarah:255; Yunus:3.
 Saaffaat:173; Mujadalah:21; Mu’min:53.
 See: Baha’uddin Khorramshahi, Jahane Ghayb va Ghaybe Jahan, pp. 45-83.
 See: Shahid Mutahhari, Moqaddame’i bar Jahanbiniye Eslami, Association of Seminary Teachers Press, p. 189.
 Kashf al-Murad fi Sharh Tajrid al-I’tiqad, p. 350.
 In the story of the magicians of the Pharaoh, when they saw Musa they understood what Musa had done was a miracle because their magic was defeated and that was when they admitted … (A’raf:105-125).
 See: Ayatullah Makarim Shirazi, Rahbarane Bozorg va Mas’uliyyathaye Bozorgtar, pp. 119-153.
 See: Al-Mizan, vol. 1, p. 82.
 See: Shahid Mutahhari, Moqaddame’i bar Jahan Bini, 1-7, p. 189; Shahid Mutahhari, Ashnayi ba Quran, vol. 2, pp 235 and on.
 See: Kashf al-Murad fi Sharh Tajrid al-I’tiqad, p. 352.
 Ibid, p. 353; Jahane Ghayb va Ghaybe Jahan, pp. 46-47.
 Through observing his obligations and divine decrees, one can gain proximity to God and as a result, attain the rank of wilayah; it is then that he can intervene in this world’s affairs.
 One of the miracles of the prophet was splitting the moon.
 In the sermon of Qaasi’ah, Imam Ali (as) recounts the miracle of splitting a tree by the prophet. Regarding the prophet’s miracles, refer to Bihar al-Anwar, lithographical print, Kompani Press, p. 105.
 Aal Imran:49.
 Bisharat al-Mustafa, printed in Najaf, p. 235; Amali, Saduq, 77th gathering, lithographical print, p. 307.
 This doesn’t mean that special individuals will not make use of it, rather, like the story of the magicians of the Pharaoh and Prophet Musa, they might be the first to make use of it.
 MirDamad; Qabasat, lithographical print, p. 321; Kashf al-Murad fi Sharh Tajrid al-I’tiqad, notes of Ayatullah HasanZadeh Amoli, pp. 597-598; Ensane Kamel az Didgahe Nahjul-Balaghah, Ayatullah HasanZadeh Amoli, pp. 8-21.
 See: Da’irat al-Ma’aarife Tashayyu’, vol. 3, p. 265; Da’irat al-Ma’aarife Bozorge Eslami, vol. 9, pp. 363-366; Al-Mizan, vol. 1, pp 58-90; Ayatullah HasanZadeh’s notes on Kashf al-Murad, pp. 597-600.
 Hud:14; Yunus:39.
 Nisa’:82; Zumar:23.
 Hud: 49; Yusuf:102; Aal Imran:44; Maryam:34; Rum:1; Fath:15; Anbiya’:97; Qasas:85; Ma’idah:67; Nur:55; Fath:27; Hijr:329; An’aam:65; Yunus:47; etc.
 Nahl:89; An’am:59; Nisa’:106; Fussilat:42; Hashr:7; Hijr:9.
 See: The different aspects of the miraculousness of the Quran
 Baqarah:23; Isra’:88.