Surah Ali'Imran, Verse 81

وَإِذۡ أَخَذَ ٱللَّهُ مِيثَٰقَ ٱلنَّبِيِّـۧنَ لَمَآ ءَاتَيۡتُكُم مِّن كِتَٰبٖ وَحِكۡمَةٖ ثُمَّ جَآءَكُمۡ رَسُولٞ مُّصَدِّقٞ لِّمَا مَعَكُمۡ لَتُؤۡمِنُنَّ بِهِۦ وَلَتَنصُرُنَّهُۥۚ قَالَ ءَأَقۡرَرۡتُمۡ وَأَخَذۡتُمۡ عَلَىٰ ذَٰلِكُمۡ إِصۡرِيۖ قَالُوٓاْ أَقۡرَرۡنَاۚ قَالَ فَٱشۡهَدُواْ وَأَنَا۠ مَعَكُم مِّنَ ٱلشَّٰهِدِينَ٨١

wa-idh akhadha l-lahu mīthāqa l-nabiyīna lamā ātaytukum min kitābin waḥik'matin thumma jāakum rasūlun muṣaddiqun limā maʿakum latu'minunna bihi walatanṣurunnahu qāla a-aqrartum wa-akhadhtum ʿalā dhālikum iṣ'rī qālū aqrarnā qāla fa-ish'hadū wa-anā maʿakum mina l-shāhidīna

And [recall, O People of the Scripture], when Allāh took the covenant of the prophets, [saying], "Whatever I give you of the Scripture and wisdom and then there comes to you a messenger confirming what is with you, you [must] believe in him and support him." [Allāh] said, "Have you acknowledged and taken upon that My commitment?" They said, "We have acknowledged it." He said, "Then bear witness, and I am with you among the witnesses."