The early Sunni Imams authored a wide array of works on zuhd (asceticism) and on the softening of the heart—such as Kitāb al-Zuhd by ʿAbd Allah ibn al-Mubārak, Wakiʿ ibn al-Jarāḥ, Aḥmad ibn Ḥanbal, Abū Dāwūd al-Sijistānī, Abū Ḥātim al-Rāzī, and many others. In all of them they were extremely careful to cite the reports of the Companions and the Successors and to place them alongside the narrations traced back to the Prophet ﷺ, knowing that no act of worship is acceptable unless it is transmitted through them.

By contrast, those who practice invented forms of asceticism revere and follow their own shaykhs while turning away from the legacy of the Companions and Successors. They try to move hearts with newly-devised devotions—such as novel litanies and the unlawful musical sessions they label “anashīd.” These practices have become the banners of activist movements and heterodox sects, including the Sufi-leaning Tablighi groups and others.

Such political activist groups combine an outward display of piety and encouragement of worship with rebellion against rulers and the declaration that they are unbelievers. This is precisely what the Prophet ﷺ foretold concerning the Kharijites: that their impressive acts of devotion would deceive people. He said:

“There will arise among you—or be found among you—people who devote themselves to worship until you marvel at them and they marvel at themselves, yet they will dart out of the religion as an arrow passes through its target.” ⦗1⦘