Is it permissible for a worshiper to prostrate during prayer other than at the place of prostration (sujud) or prostration of recitation (sujud at-tilawah), especially when reciting verses that mention Paradise, Hellfire, and the greatness of Allah? And does the ruling differ between supererogatory prayers and the prayer of a congregant behind an imam?

The Prophet, peace and blessings be upon him, taught his Ummah how to pray, both in word and deed. Therefore, it is not permissible for anyone to deviate from the form of prayer that the Prophet, peace and blessings be upon him, taught. Rather, a Muslim must adhere strictly to the Sharia. Scholars have agreed that whoever intentionally adds an extra bowing (ruku'), prostration (sujud), or standing (qiyam) to the prayer has invalidated it. This applies to the Imam, the follower (ma'mum), and the individual praying alone. An intentional addition of an act that is of the same type as the prayer (such as standing where one should be sitting, or prostrating out of place) invalidates the prayer by the consensus of scholars. It is not permissible to prostrate in prayer out of its proper place unless the worshiper recites a verse of prostration. In this case, the Imam and the individual praying alone prostrate, and the follower prostrates if his Imam prostrates. There is no difference in this regard between voluntary (nafilah) and obligatory (faridah) prayers.