Shaykh al-Islām—may Allah have mercy on him—said:

Section: Acts of Worship Prescribed in Different Forms

It has already been explained in several places that when the Prophet, peace and blessings be upon him, performed an act of worship in different ways, all those forms are prescribed, and none is disliked. Examples include the different forms of the tashahhud (testimony of faith recited while seated in prayer) and the opening supplications; performing Witr prayer at the beginning or end of the night; reciting aloud or quietly during the night prayer; the various readings in which the Quran was revealed; proclaiming Allah’s greatness on Eid; including or omitting tarjīʿ (repetition of the testimonies of faith after reciting them quietly) in the call to prayer; and saying the phrases of the iqāmah (final call to prayer) once or twice.

In our response to the Zarʿiyyah questions and elsewhere, we have explained at length that matters over which scholars differ, and concerning which a person wishes to exercise caution, fall into two categories:

The first consists of matters in which they agree that both alternatives are permissible, but differ as to which is preferable.