For adopting a particular garb or outwardly professing a doctrine is no greater than professing Islam. If, even among those professing Islam in the Prophet’s time—may Allah bless him and grant him peace—and in every age, there were many hypocrites, then such people are to be found among all groups affiliated with learning and worship.

In the two Sahīh collections, Abū Mūsā al-Ashʿarī reported that the Prophet, may Allah bless him and grant him peace, said:

“The believer who recites the Quran is like a citron: its taste is pleasant and its fragrance is pleasant. The believer who does not recite the Quran is like a date: its taste is pleasant, but it has no fragrance. The hypocrite who recites the Quran is like an aromatic herb: its fragrance is pleasant, but its taste is bitter. The hypocrite who does not recite the Quran is like a colocynth: its taste is bitter, and it has no fragrance