However, Allāh says, {We have neglected nothing in the Book} (Qurʾān 6:38); therefore, if the Qurʾān contains everything we need, why would there be any need for the Sunnah?

The verse 6:38 that the Qurʾānists cite in support of their claim is quoted in a truncated manner, as they omit a significant portion of it. When the verse is read in its entirety, the surrounding context and the flow of the passage make it clear that Allāh is not speaking about the Qurʾān at all, but rather about something entirely different, as Allāh says: {all living beings roaming the earth and winged birds soaring in the sky are communities like yourselves. We have neglected nothing in the Book. Then to their Lord they will be gathered all together} (Qurʾān 6:38). The word “Book” mentioned here does not refer to the Qurʾān, but rather to al-Lawḥ al-Maḥfūẓ (the Preserved Tablet). That is, the verse affirms that knowledge of all things rests with Allāh alone. In other words, Allāh never forgets any of His creatures, whether they dwell on land or in the sea, and all their names, numbers, movements and stillness, sustenance, and affairs are already recorded in al-Lawḥ al-Maḥfūẓ, which is the Book of Decrees. Does the Qurʾān itself contain detailed knowledge of all living creatures? Most certainly it does not. One might then object by citing the verse in which Allāh says, {We have revealed to you the Book as an explanation of all things} (Qurʾān 16:89), where the Qurʾān is described as an exposition of everything, yet since it does not include the detailed rulings of every religious matter, how can this description be correct? The answer is that the Qurʾān lays down the foundational principles for all religious matters, and it is through these principles that the Sunnah of the Prophet (PBUH) elucidates them. Thus, Allāh has revealed the Qurʾān as an explanation of everything together with the Sunnah. One may think of it in the following way: the Qurʾān is akin to a comprehensive constitution, and it is well known that a constitution sets out the fundamental laws and principles by which a state is governed, without containing every specific rule regulating what its people may or may not do. Law, rather, is the broader system of rules that governs societal conduct and thus encompasses the constitution itself. In the same manner, the Sunnah provides the detailed elaboration of the general principles laid down in the Qurʾān and serves as the lens through which it was understood.

It is commonly acknowledged that the Qurʾān does not supply detailed rulings for most matters—indeed, 86 of the 114 Qurʾānic chapters do not address any aḥkām (legal rulings) at all.¹ Once again, the Qurʾān establishes the foundational bases and principles of legislation, whereas the Sunnah provides both their theoretical interpretation and their practical application. This naturally raises the question of how those who reject the Sunnah are able to pray, fast, give zakāt (obligatory charity) from their wealth, or perform ḥajj (the major pilgrimage to Makkah, performed at a specific time of the year and consisting of prescribed rites) and ʿumrah (the minor pilgrimage to Makkah, which may be performed at any time of the year and involves fewer rites than ḥajj), given that the detailed rulings governing these acts of worship are not stated in the Qurʾān itself but are instead elaborated in the Prophetic Sunnah. Moreover, the Qurʾān is described as an explanation of everything in the sense that it directs Muslims to the source from which they obtain the detailed clarification of rulings that are mentioned only concisely within it. For instance, Allāh commands the believers in the Qurʾān, saying: {Establish prayer} (Qurʾān 2:110). This verse affirms the obligation of prayer without specifying its times, number of units, rulings, conditions, or any other related details, all of which the believers learn through the practices of the Prophet (PBUH). That is, the Prophetic Sunnah explained what was stated briefly in the Qurʾān. The Prophet (PBUH) taught the believers all matters pertaining to prayer and instructed them to pray in the way they saw him praying. As previously noted, this same pattern applies to the other acts of worship, which are mentioned succinctly in the Qurʾān and then detailed through the Prophetic Sunnah. Hence, Allāh commands Muslims to follow the Sunnah because without it the Qurʾān cannot be properly understood or implemented. Put another way, the duty entrusted to the Prophet (PBUH) was not merely to convey the verses revealed to him from Allāh, but also to explain them: {and We have sent down to you ˹O Prophet˺ the Reminder, so that you may explain to people what has been revealed for them, and perhaps they will reflect} (Qurʾān 16:44). Once again, the Sunnah represents the practical implementation of the Qurʾān, and this verse directly refutes the view of the Qurʾānists who claim that the Qurʾān alone is sufficient and should be accepted without any explanation from the Prophet (PBUH). Such a view contradicts the meaning of the verse itself, as it would imply that the Prophet (PBUH) failed to fulfill the very purpose for which he was chosen to bear the Book—namely, to explain its teachings both verbally and through practice. By adopting this view, the Qurʾānists also implicitly accuse Allāh of acting without wisdom by sending His Book through a Prophet, when He could have sent it through an angel or directly to every individual. Contrary to their claim, however, Allāh explicitly states in the aforementioned verse (16:44) that the presence of a Prophet is indispensable and that his exposition of the Book is an essential matter. This is why the actions and statements of all the Companions were in complete harmony with both the Qurʾān and the Prophetic Sunnah, as illustrated by the statement of Jābir ibn ʿAbd Allāh [may Allāh be pleased with him]: “…the Messenger of Allāh (PBUH) was among us, and the Qurʾān was being revealed to him and he knew its interpretation, and whatever he acted upon from it, we acted upon as well.”²

Those who reject the Sunnah, claiming that “we have no need for the Sunnah because the Qurʾān is sufficient,” cite the following verse in support of their position: {Is it not enough for them that We have sent down to you the Book, ˹which is˺ recited to them} (Qurʾān 29:51). This is yet another example of their misuse of a verse by taking it out of context. Let us read this verse together with the verse that precedes it. Allāh says: {they say, “If only ˹some˺ signs had been sent down to him from his Lord!” Say, ˹O Prophet,˺ “Signs are only with Allāh. And I am only sent with a clear warning.” Is it not enough for them that We have sent down to you the Book, ˹which is˺ recited to them} (Qurʾān 29:50–51). The idolators persistently demanded miracles, believing that seeing one would convince them that Muḥammad is truly a Prophet of Allāh. In response, Allāh said: is not the Qurʾān itself—a great Book that passes judgment between them, recounts what occurred before their time, and foretells what will happen after they are gone, revealed to the Prophet (PBUH) despite his being an unlettered man who once grazed the sheep of the Makkans for a few carats (a carat being one-twentieth, or slightly more, of a dinar)—sufficient as a miracle to confirm Muḥammad’s Prophethood? This verse makes it unmistakably clear that the Qurʾān, miraculous in its legislation, as well as in its eloquence and argumentation that softens hearts, calms souls, and illuminates reason and perception, is the greatest miracle and the strongest proof of Muḥammad’s Prophethood. Consequently, this verse has nothing to do with the position of those who reject the Sunnah, claiming that “the Qurʾān is enough; we interpret it ourselves and have no need for the Sunnah.” In short, the Qurʾānists’ doctrine is incompatible with Islam, because turning one’s back on the Sunnah is, in effect, opposing the Qurʾān itself. Sadly, in their eagerness to reject the Sunnah, the Qurʾānists fail to realize that they are cutting at the very root of Islam.