In what sense does the Quran ‘confirm’ earlier scriptures?

It is well known that the Quran affirms earlier prophets, revelations, and scriptures, including the Tawrah (Law) given to Moses, and the Injil (Gospel) given to Jesus - peace be upon them. As the final revelation to the final messenger, Prophet Muhammad ﷺ, the Quran serves as the “guardian” (muhaymin) over all scripture.

Concerning the description of the Quran as “guardian”, Ibn ‘Atiyyah comments: “The exegetes have used different expressions to capture the meaning of muhaymin. Ibn ʿAbbas said it means ‘witness’. He also said it means ‘entrusted’. Ibn Zayd said its meaning is ‘confirmer’. Al-Hasan b. Abi al-Hasan said it means ‘trustworthy’. Al-Zajjaj mentioned ‘overseer’. The word muhaymin is more specific than these expressions because the one who is muhaymin over something is responsible for it, witnessing its truths, and safeguarding its essence, not allowing anything foreign to enter it. Allah, the Blessed and Exalted, is the Muhaymin over His creations and servants. A guardian is muhaymin over his wards and their wealth, and a ruler is muhaymin over his subjects and their affairs. Allah made the Quran muhaymin over the [previous] books, bearing witness to what is true within them and clarifying the distortions made by those who altered them. Thus, it affirms their truths and falsifies any distortions. Thus it is witness, confirmer, trustee, and guardian.”

The Quran affirms the truthfulness of the divine books revealed before it by upholding the same core message and teachings even though specific rulings may change. Some rulings remain the same while others are abrogated. The Quran also distinguishes the true teachings contained in these scriptures from the false teachings and corruptions of the text. Hence, if they are ever looking at earlier scriptures, Muslims should compare their contents with the Quran to know what to accept and what to reject as a distortion.

Some commentators, such as al-Sam’ani, have stated that the true books of God are the ones whose message is confirmed to be true by the Quran, while those that are at odds with the Quran are not. On this basis, the likes of Paul’s epistles are not recognised as scripture from an Islamic perspective.

The Quran acts as the “guardian” over previous scriptures by providing the basis to accept or reject the statements found in them after its revelation.