It is known that Allah mentions listening to whistling and clapping in the Quran only in connection with the polytheists, and that it is never free of some form of shirk, whether overt or hidden. Hence, He relates how those false things had initially appeared to them, as He, Most High, says:

“Like a mirage in a lowland which a thirsty person mistakes for water, until, when he reaches it, he finds it to be nothing, but finds Allah there.”
[Surah al-Nūr 39]

Nevertheless, among those meanings that are witnessed and then veiled, there may also be realities of faith in which believers rejoice. Were it not for this element, some believers would not have been misled by it. Yet truth has been mixed with falsehood in it; this practice is by no means pure truth. It is because of the truth it contains that it has gained acceptance among those believers who have embraced it, including their ascetics, Sufis, faqīrs, and devout worshippers. But it gained acceptance among them because of the weakness of their faith. Had they attained complete faith, they would have recognized the shirk it contains and its mingling of truth with falsehood.

Thus, this becomes clear to those among them whose faith Allah wills to perfect, and they repent of it. This is what is reported of the great majority of the leading shaykhs who attended such gatherings: they repented of them, just as many leading scholars repented of the innovations in speculative theology in which they had become involved.

Abū al-Qāsim said: “I heard Muhammad ibn Ahmad ibn Muhammad