Islam reprimands those who do not refrain from acquiring and consuming haram property since it leaves negative impacts on human's soul and heart as well as his family. Many sins are deeply rooted in man’s polluted soul.
Environment also influences human's behavior and plays an important role in building or destroying human's character. The impact of haram property and corrupt environment, however, is only the condition and insufficient cause as it may create the ground for deviation in man and his progeny rather than denying him and his children volition and free will. There may be a child born to non-Muslim parents who starts to follow the right path because he moves toward perfection of his own free will in consonance with his God-gifted nature.
It should be mentioned that voluntary use of haram property affects the human soul more profoundly than when the child is under involuntary conditions. Children who have been brought up in families where the use of haram property is commonplace and have voluntarily chosen the right path after puberty have in fact not committed any haram deeds and they tend to accept more spiritual development than those who have deliberately chosen to earn and live on haram properties. Therefore the use of haram property has wadh’ei (declaratory) effect on children but not to an extent that defies or challenges his free will. In fact, it serves only as a ground.
The impact of haram morsel of food on man’s fate
Every action leaves a trace and an impact in this universe, although in some cases it may not be seen with the eyes. Among them is the impact of haram food on human character and soul. Halal and haram food stuffs look similar to us but haram food leaves an influence on human soul and character discovering which is beyond the grasp of man's superficial knowledge.
From the viewpoint of Islam and common sense, one who does not avoid haram food has been denounced because it leaves harmful impacts on human soul and heart. Many sins are deeply rooted in a corrupt human soul. Haram food contaminates human soul as polluted water causes diseases in human body.
The holy Quran says:" And do not swallow up your property among yourselves by false means, neither seek to gain access thereby to the judges, so that you may swallow up a part of the property of men wrongfully while you know." Although God Almighty has put forth an instance of haram property but He reminds humans of a general principle i.e. any form of unlawful control over other people's properties is declared haram by Him and must be avoided.
Here are some negative impacts of haram property or food based on traditions:
1-The Holy prophet (PBUH) has said: "One who earns a property through non-halal means, that property would be his provision for the hell."
2-He has said: "God has an angel in Bayt al-Muqaddas who calls every night that no mustahhab and no wajib act will be accepted from someone who consumes haram property."
3-Imam Sadeq (PBUH) says: "Acquisition of haram property will demonstrate its effects on the person's progeny."
It is therefore inferred from Quranic verses and traditions that in order for us to have uncorrupt, religious and good-tempered children the economic source or the source of livelihood should be halal, and haram properties should be avoided so that the education may become effective.
It is necessary to mention that the impact of voluntary use of haram properties is more profound than its natural or declaratory impact under involuntary conditions. Since eating haram food can not be voluntary for a child, he does not deserve chastisement. However, it will diminish the capabilities for spiritual progress. Children who have been reared in families where the use of haram property has been commonplace and they have voluntarily chosen the right path after puberty trying to use halal properties, in fact, have not committed a haram deed and their capability for spiritual growth is more than those who have deliberately earned haram properties. It is true that these kinds of properties will have their wadh’ei (declaratory) effect on children's souls but not as much as to challenge their free will but they only serve only as a ground. Therefore if some people have used haram properties but have ended up becoming good and virtuous people, it is because the impact of haram property is only a condition an insufficient cause.
Thus earning haram property undoubtedly paves the ground for negative tendencies in a person who uses haram properties and his progeny but not to a point which can negate the person's free will and his family's. There may be a child from non-Muslim parents but follows the right path; because man can make up this shortcoming with his free will and knowledge; when he figures out that his properties are haram he repents and returns people's properties and makes up for their rights reaching salvation by acquiring halal property and becoming a virtuous and a good-doing person.
The Role of Environment on Man’s Upbringing
Environment is among the effective factors in human's upbringing. Undoubtedly, environment has an impact on man's words and deeds and plays a really profound role in construction or destruction of his personality. It is an irrefutable fact that humans are influenced by environment and its different situations but is it possible to act in such a way not to be influenced by inappropriate and corrupt environment? The answer is that man has free will on which depends his perfection. If man treads the divine path knowing the obstacles, the corrupt environment can not influence him.
The holy Quran introduces some means to resist the inappropriate environment two of which are mentioned below:
1-Awareness: Basically, the spirit of Islamic teachings does not correspond with ignorance and it is not possible to achieve, perfection, proximity to God and a prestigious status in society without science and knowledge. Islam is a comprehensive and multi-dimensional religion. In the same way that prayers and fasting are important seeking knowledge is also of paramount importance. Revival of human spirits and psychology is impossible without the awareness obtained through authentic knowledge and truth. Imam Ali (AS) says: “Knowledge revives the human spirit.” Although Prophet Moses’ companions would always benefit from his advice but since they were ignorant they would be influenced by environment and public display of idolatry. Moses (AS) reprimanded them and said: “Surely you are a people acting ignorantly; (As to) these, surely that about which they are shall be brought to naught and that which they do is vain.”
2-Reforming the current status: to eradicate certain unacceptable behaviors and to create appropriate behaviors and modes of conduct we should start changing the unacceptable environment of our surroundings. A change in human relations accompanied with a change in times, location and social conditions is the starting point for many developments in behavior.
When Moses (AS) was away from his people for a short time, Sameri took advantage of his absence and gave his people a fascinating golden calf made out of gold and jewelry borrowed from them. As for those who followed Sameri, they were involuntarily captivated by that calf, prostrated before that and considered it as their deity. When Moses (AS) returned and found his people trapped in Sameri’s conspiracy, he called him and said to him: “He said: Be gone then, surely for you it will be in this life to say, Touch (me) not; and surely there is a threat for you, which shall not be made to fail to you, and look at your god to whose worship you kept (so long); we will certainly burn it, then we will certainly scatter it a (wide) scattering in the sea.”
To handle polytheistic concepts among people, Moses (AS) changed the status expelled Sameri out of his people and cleaned the traces of Sameri’s misguiding measures from the society and by doing so he nipped the conspiracy in the bud.
When it comes to the individuals named in the question we say:
Although Moses (AS) lived in Pharaoh’s house but we know that due to faith, knowledge and complete conviction they had an indisposition whereby they did not approach any sins and mistakes of their free will and choice. In fact, they did not even think about committing any sins. Moreover although Moses (AS) has been in Pharaoh’s house, but it does not necessarily mean that he had served haram food, rather God provided him with halal food as He also protected him when he was being carried along the Nile river. As for Asiya, it cannot be said that since she was is Pharaoh’s house she cannot become a good doer; because it is not known if she had haram food. Secondly, haram food, as mentioned earlier, cannot be a complete and adequate cause.
About Mu’awiyah II we should say although he was Yazid’s son but he realized that his grandfather, Mu’awiyah and his father, Yazid’s act was wrong and therefore he relinquished from power and stopped calling himself a caliph, a praiseworthy action on his part.
When it comes to Harun al-Rashid’s sons it is necessary to say that in the year 186 of the Islamic calendar, Harun al-Rashid took allegiance for Qasem, his third son, to be the crown prince after Amin and Ma’moon. He called Qasem as Mo’tamen and made him the governor of the Island although he was just a child. If we Qasem were presumably a good person, we give the answer we already provided in regards to the abovementioned individuals.
 Quran 2:188 “And do not swallow up your property among yourselves by false means, neither seek to gain access thereby to the judges, so that you may swallow up a part of the property of men wrongfully while you know.”
 See: Makarem Shirazi, Naser, Nomoune Quran Exegesis, vol.2 ,p.3-4, Darul Kotob al-Eslamiia, Tehran, first print, 1996; Tabataba’i, Seyyed Muhammad Hussein, Al-Mizan Quran Exegesis, translated by Mousavi Hamadani, Seyyed Muhammad Baqer, vol.2, p.73-74, Islamic Publications Office of The Society of Qom Seminary Teachers, 5th print, 1996
 Majlesi, Muhammad Baqer, Beharul Anwar, vol.100, p.10, Alwafa Institute, Beirut, Lebanon, year 1404 from lunar hijri calendar
 The same, p.16
 Theqatol Eslam Kolaini, Al-Kafi, vol.5, p.124, Darul Kotob al-Eslamiia, Tehran, 1987
 Quran 17:64, “And beguile whomsoever of them you can with your voice, and collect against them your forces riding and on foot, and share with them in wealth and children, and hold out promises to them; and the Shaitan makes not promises to them but to deceive”
 Beharul Anwar, vol.101, p.136
 See Norouzi, Muhammad, behavioral Pathology from Quranic Viewpoint, p.66-69 ,Publishing and printing center of Qom Islamic Propagation Office, Qom, Third print, 2008; Shokouhi, Mohsen, Islamic Education and Training, p.85, Teacher Training Center; Mahdavi, Seyyed Saeed, A Look into Story and its Educational Points in Quran, p.222-230, Publishing and printing center of Islamic Propagation Office, Qom, Second print, 2008
 A Look into Story and its Educational Points in Quran, p.225-228
 Tamimi Amodi, Abdol Wahed bin Muhammad, Gorarol Hekam, p.63, Qom Islamic Propagation Publications, 1988
 Quran 7:138-139
 A Look into Story and its Educational Points in Quran, p.229-230
 Quran 20:97