—it is impossible to cite part of it as proof while discarding the rest, no matter whether you presume them to be truthful or false.

Hence, in every possible case—whether they acknowledge that he was sent as a prophet to the Arabs or to others, deny his claim that he is the Messenger of Allah, remain silent on both counts, or believe him in some matters while rejecting him in others—we say to them: Your attempt to validate, by means of what Muhammad ﷺ brought, those doctrines in which you disagree with the Muslims is invalid from every angle. To appeal to any passage of the Qur’an to argue that he was not sent to you, or to vindicate the soundness of your religion, is a groundless plea in every respect.

Nevertheless, we shall, God Most High willing, demonstrate that all the revealed scriptures, together with sound reason, furnish you with no support whatsoever; rather, they are all proofs against you.

The situation is entirely different for the Muslims. It is perfectly legitimate for them to argue against the People of the Book—Jews and Christians—on the basis of what the prophets before Muhammad ﷺ brought, whereas the People of the Book are not entitled to argue on the basis of what Muhammad ﷺ brought. This is because the Muslims affirm the prophethood of Moses, Jesus, David, Solomon, and the rest of the prophets, peace be upon them all, and they hold it obligatory to believe in every book Allah has revealed and every prophet He has sent. This is a foundational principle of the Muslim faith: whoever disbelieves in even one prophet or in a single revealed book is, in their view, an unbeliever—indeed, anyone who reviles any prophet is deemed an unbeliever.