رَبَّنَآ ءَامَنَّا فَٱكۡتُبۡنَا مَعَ ٱلشَّـٰهِدِينَ.

Our Lord, we have believed, so register us among the witnesses.

Rabbana amanna faktubna maa shshahidin

These words were spoken by Christians who saw and accepted the Truth of Islam once they had heard Allah’s verses. Upon accepting Islam, they declared their faith and asked Allah to register them along with the ‘witnesses’, who are, in fact, the Muslims. -Tafseer As-Sa’di.