It has been mentioned in fiqh (jurisprudential) books that one of the recommended recitals of Tashahhud is that the person offering prayers should, in the first and second Tashahhuds, recite the words that have been narrated by Abu Basir from Imam Sadiq (a.s.). The words that are recommended to be recited in the first Tashahhud of the second Rak’at are:

«بسم اللَّه و باللَّه، و الحمد للَّه و خیر الأسماء للَّه، أشهد أن لا إله إلّا اللَّه وحده لا شریک له، و أشهد أنّ محمَّداً عبده و رسوله، أرسله بالحقّ بشیراً و نذیراً بین یدی الساعة، أشهد أنّک نعم الربّ، و أنّ محمَّداً نعم الرسول، اللّهمَّ صلّ على محمَّد و آل محمَّد، و تقبّل شفاعته فی أُمّته و ارفع درجته»

(Bismillahi wa billahi wal-hamdu lillahi wa khayrul asma’i lilah, ashhadu an la ilaha illallah wahdahu la sharika la wa ashhadu anna muhammadan abduhu wa rasuluhu arsalahu bilhaqqe bashiraw-wa-naziran bayna yadayis sa’ah ashhadu annaka ne’mar-Rab wa anna muhammadan ne’mar-Rasul, allahumma salli ‘alaa muhammad wa aal-e muhammad wa taqabbal shafa’atahu fi ummatihi war-fa’ darajatah.”

Then in the second Tashahhud, it is recommended to recite:

«بسم اللَّه و باللَّه و الحمد للَّه و خیر الأسماء للَّه أشهد أن لا إله إلّا اللَّه وحده لا شریک له، و أشهد أنّ محمَّداً عبده و رسوله، أرسله بالحقّ بشیراً و نذیراً بین یدی الساعة، أشهد أنّک نعم الربّ، و أنّ محمّداً نعم الرسول، التحیّات للَّه، و الصلوات الطاهرات الطیّبات الزاکیات الغادیات الرائحات السابغات الناعمات ما طاب و زکى و طهر و خلص و صفى فللّه أشهد أن لا إله إلّا اللَّه وحده لا شریک له، و أشهد أنّ محمَّداً عبده و رسوله أرسله بالحقّ بشیرا".

(Bismillahi wa billahi wal-hamdu lillahi wa khayrul asma’i lilah, ashhadu an la ilaha illallah wahdahu la sharika la wa ashhadu anna muhammadan abduhu wa rasuluhu arsalahu bilhaqqe bashiraw-wa-naziran bayna yadayis sa’ah ashhadu annaka ne’mar-Rab wa anna muhammadan ne’mar-Rasul, at-tahiyatu lillah was-Salawatut-Taherat at-tayyibat az-zakiyat al-ghadiyat ar-raehat assabeghat anna’emat ma taba wa zaka wa tahora wa khalasa wa safa, fa lillah-e ashhadu an la ilaha illallah wahdahu la sharika la wa ashhadu anna muhammadan abduhu wa rasuluhu arsalahu bilhaqqe bashiran.)[1]

Late grand Ayatollah Gulpaigani says in an answer to a question in this regard: “Tashahhud narrated by Abu Basir is mentioned in Al-Urwatul Wuthqa. They should recite it in the same way as narrated. However, since this is a secondary issue, the followers (muqalledin) should not recite more than what has been prescribed in Resalah Amaliyah (the book of Islamic Laws).[2] It should be noted that the sentence “wa anna alian ne’mal wasi wa ne’mal-imam” neither exists in the narration nor does it exist in Al-Urwatul Wuthqa.

Therefore, there is no problem in reciting the zikr that has been mentioned in the text of Al-Urwatul Wuthqa, albeit not as a part or as wajib but as a recommended zikr. In case, it is recited as a part of the prayers, it would be invalidating.