The Accusation that the Prophet was a Madman and Demands for Him to bring down Angels
Allah tells us about the disbelief, arrogance and stubbornness of the disbelievers as reflected in their words:
يأَيُّهَا الَّذِى نُزِّلَ عَلَيْهِ الذِّكْرُ
(O you (Muhammad) to whom the Dhikr (the Qur'an) has been revealed!) i.e., the one who claims to receive it.
إِنَّكَ لَمَجْنُونٌ
(Verily, you are a mad man!) i.e., by your invitation to us to follow you and leave the way of our forefathers.
لَّوْ مَا تَأْتِينَا بِالْمَلَـئِكَةِ
(Why do you not bring angels to us) i.e., to bear witness to the accuracy of what you have brought to us is true, if you are really telling the truth This is similar to what Pharaoh said:
1. The word: الْحَقِّ (what is true) in: إِلَّا بِالْحَقِّ (ilia bi al-l aqq: translated as 'except with what is true' ) means the decision to send down punishment. Some commentators take them to be denoting the Qur’ an, or prophethood. In Bayan al-Qur'an, preference has been given to the first meaning which has been reported from al-Hasan al-Basri (رح) . Maulana Ashraf ` Ali Thanavi (رح) has explained these verses as given below.
And these disbelievers (of Makkah) said to the Holy Prophet ﷺ : "0 you to whom the Qur’ an has been revealed, (as you claim, then,) you are certainly (God forbid) insane (and your claim to prophethood is false, otherwise) why would you not bring the angels to us (who will testify your truthfulness before us - as in Surah Al-Furqan: لَوْلَا أُنزِلَ إِلَيْهِ مَلَكٌ فَيَكُونَ مَعَهُ نَذِيرًا : 'Why is not an angel sent down unto him, to be a warner with him? [ 25:7] which is answered by Allah Ta’ ala:) We send down the angels (in the manner asked by them) only to enforce a decision (and had that been the case) then they would have been given no respite either (in fact, when they would have not believed even after their having come - as their ways guarantee - they would have been destroyed instantly, the reason for which has already appeared in the later verses of the first section of Surah Al-An’ am: 6:8, 9).
Tazkirul Quran
Maulana Wahiduddin Khan
The addressees of the Prophet Muhammad suspected him of being mad. What was the reason for this? The reason for this was his declaration that he was a representative of God; that one who accepted his word would be successful, while one who did not would remain a failure. But the addressees themselves actually perceived things to be just the opposite. They were of the view that the prevalent system had bestowed the position of leadership on them. On the contrary, the Prophet, due to his being a preacher of an unconventional religion, was a stranger and a man without a status in the prevalent system. Because of these apparent shortcomings, the addressees were emboldened to say that he (the Prophet) appeared to them to be a madman. They said, ‘God has given us all kinds of worldly glories, yet still you say that success lies with you and your supporters.’ But such thinking was caused by a difference in perception. The addressees regarded whatever was material in their possession as ‘rewards’, though all of these things were simply a means of trial, given to all and sundry on a temporary basis. They also used to say, ‘You claim that the angels of God come to you. Then why are these angels not visible to us?’ This comment too was due to a difference of point of view. An angel who comes to a prophet is the angel of revelation. He brings God’s words to the prophet. Besides this angel there are other angels of God who come to the people in order to uncover the reality to them. But they come after the process of conveying the truth to the people is over. And when they come, it is the time for judgement and not the time for calling people to the faith.
Uthmani text of the Madinah mushaf (King Fahd Complex). Translation: Saheeh International. Tafsir via Quran.com.