—and the path, the orientation, and the devotional rites; yet none of this prevents the religion itself from remaining one, just as similar variety within the law of a single messenger does not break its unity.

[The first of the messengers foretells the last, and the last confirms the first]

Allah, Exalted is He, made it an article of the messengers’ religion that the earliest of them should give glad tidings of the one who comes after them and believe in him, while the last of them should affirm those who preceded him and believe in them. He, the Most High, says: “And [remember] when Allah took the covenant of the prophets: ‘Whatever I give you of the Book and wisdom, then there comes to you a messenger confirming what is with you—you must believe in him and support him.’ He said, ‘Do you affirm and accept My binding word?’ They said, ‘We affirm.’ He said, ‘Then bear witness, and I am with you among the witnesses.’” Ibn ʿAbbās (may Allah be pleased with them both) said: “Allah never sent a prophet without first taking from him the covenant that, if Muhammad were sent during his lifetime, he would surely believe in him and support him; and He commanded that prophet to exact the same covenant from his nation: that if Muhammad were sent while they were still alive, they would believe in him and support him.”