Replacing the Prostration of Recitation With the Phrase "La Ilaha Ila Allah"

Question :

When we read a verse of the Qur'an that requires us to prostrate, and when we are in a place other than the Masjid or prayer room, we say four times, "La Ilaha Ila Allah Wahdahu La Sharika Lahu, Lahul-Mulku Walahul-Hamdu Wahuwa 'Ala-Kulli-Shayin-Qadir (None has the right to be worshipped except Allâh alone, and He has no partner; the entire dominion belongs to Him; all praise is for Him; and He is upon all things capable). Is this permissible? If not, what should we do?

Answer:

When one is reciting a verse of prostration in the Qur'an, it is recommended and not compulsory to prostrate, according to the preferred view.

This is because it is confirmed that on one Friday, "Umar, may Allah be pleased with him, recited a verse of prostration during the Khutbah, and so he prostrated; the following Friday, he recited the same verse, but did not prostrate. He said, "Indeed, Allah has not made prostration obligatory upon us unless we wish."

If you do not prostrate, you should not say something to replace the prostration, because doing so is an innovation. When Zaid bin Thabit recited Surat An-Najm in the presence of the Prophet he didn't prostrate, and the Prophet didn't teach him to say something as an alternative to prostrating.

Source:
Ibn 'Uthaimin
Fatawa Islamiyah, Vol. 7 Pages 88-89