In another wording he ﷺ said, “Whoever carries out an act that is not in accordance with our command, it is rejected.” (1)

2 – Categories of innovation

Religious innovation falls under two main headings:

The first type: doctrinal innovations in speech and belief, such as the teachings of the Jahmiyyah, the Mu‘tazilah, the Rāfiḍah, and all other deviant sects and their creeds.

The second type: innovations in devotional acts. This refers to worshipping Allah through a practice He has not legislated, and it comprises several subdivisions:

Section One: introducing an entirely new act of worship that has no basis in the Sacred Law—for example, inventing a prayer that is not prescribed, instituting a fast for which there is no sanction, or establishing non-legislated festivals such as birthday celebrations and the like.

Section Two: adding to an act of worship that is already legislated, as when someone inserts a fifth unit (rak‘ah) into the noon (ẓuhr) or afternoon (‘aṣr) prayer, for instance.