to his Companions, “Is any one of you incapable of reciting one-third of the Quran in a single night?” They found that hard, so he recited: “Say: He is Allah, the One; Allah, the Eternal Refuge; He neither begets nor is born; and none is comparable to Him” (Q 112), and said, “It is equal to one-third of the Quran.”

What he meant is that its reward matches the reward for reciting a third of the Quran, not that it can take the place of the Quran itself. Therefore, if someone were to recite it, for example, three times instead of al-Fātiḥah during the prayer, it would not suffice, because there is a difference between equivalence in reward and equivalence in legal sufficiency. A deed may match another in reward yet fail to substitute for it in discharge.

Consider the statement: “lā ilāha illa Allah waḥdahu lā sharīka lah, lahu ’l-mulk wa-lahu ’l-ḥamd, wa-huwa ʿalā kulli shayʾin qadīr” (There is no deity worthy of worship but Allah alone, without partner; to Him belongs the dominion and the praise, and He has power over all things). Whoever says it ten times receives the reward of emancipating four persons from among the descendants of Ishmael—that is, it equals the freeing of four slaves in reward. Yet if someone owed the expiation of freeing a slave and merely recited this formula, it would not fulfill that obligation. Thus there is a clear distinction between equivalence in merit and equivalence in discharge.

Accordingly, Sūrat al-Ikhlāṣ equals one-third of the Quran in reward, but not in legal sufficiency; so if a person were to recite it three times in prayer, it would not substitute for al-Fātiḥah. Allah is the One who grants success.