[Pooya/Ali Commentary 16:89] The Holy Prophet, who came with the book ( a guide, a mercy and glad tidings to those who submit themselves to Allah) explaining all things, is a witness over all the witnesses. In addition to verses mentioned in the commentary of verse 84 of this surah, please refer to Bani Israil: 71 and An Nur: 24.
Evidence given by a witness can be accepted only when the witness has witnessed the event which is being examined. Every messenger of Allah will give evidence about the response of his people to whom he was sent to preach the message of Allah; while the Holy Prophet will be a witness over all the prophets and messengers of Allah who will be raised as witnesses over their respective followers.
The Holy Prophet said:
"I was the prophet of Allah when Adam was in the process of creation."
It implies that he was present in this world from the very beginning and will be here till the end to witness that which had happened and that which is taking place. It is nothing but a fabricated and mischievous tale, very popular among the common Muslims, that when Jibra-il came to him he could not recognise him, and was frightened so much that he began to tremble in fear; and at last came to his senses when his wife and her uncle, Warqa bin Nawfil, told him that he was chosen as the last messenger of Allah.