The following hadith, found in Sahih Bukhari which is the most authentic and the most revered collection for the Sunnis, narrates the sequence of events after the Holy Prophet (صلى الله عليه واله وسلم) first received revelation from the angel Gabriel (عليه السلام).
Sahih Bukhari, Volume 9, Book 87, Number 111
Narrated 'Aisha:
Then Allah's Apostle returned with the Inspiration, his neck muscles twitching with terror till he entered upon Khadija and said, "Cover me! Cover me!" They covered him till his fear was over and then he said, "O Khadija, what is wrong with me?"…
…the Divine Inspiration was also paused for a while and the Prophet became so sad as we have heard that he intended several times to throw himself from the tops of high mountains and every time he went up the top of a mountain in order to throw himself down, Gabriel would appear before him and say, "O Muhammad! You are indeed Allah's Apostle in truth" whereupon his heart would become quiet and he would calm down and would return home. And whenever the period of the coming of the inspiration used to become long, he would do as before, but when he used to reach the top of a mountain, Gabriel would appear before him and say to him what he had said before.
1) The Sunnis claim the Prophet was terrified and did not know what happened to him when he received revelation. He supposedly said, “What is wrong with me”? It is completely wrong to claim the Prophet was in that confused and poor state of mind regarding his Prophethood, and it is a borderline attack on his holiness and nobility.
We also find in Sahih Bukhari:
Volume 7, Book 71, Number 670:
Narrated Abu Huraira:
The Prophet said, "Whoever purposely throws himself from a mountain and kills himself, will be in the (Hell) Fire falling down into it and abiding therein perpetually forever; and whoever drinks poison and kills himself with it, he will be carrying his poison in his hand and drinking it in the (Hell) Fire wherein he will abide eternally forever; and whoever kills himself with an iron weapon, will be carrying that weapon in his hand and stabbing his abdomen with it in the (Hell) Fire wherein he will abide eternally forever."
Are the Sunnis willing to accept the Prophet was only prevented from doing that by an angel, and that he considered and contemplated suicide. We seek refuge from such things.
2) If we could tolerate the above, what comes next is just too shocking. According to this narration, the Prophet Mohammed was suicidal, and we seek refuge in Allah (عز و جل) from such blasphemy. How can the Prophet, who was free from sin, and was at the pinnacle of piety and the Messenger of Allah, contemplate suicide? Not only is that outrageous based on the fact suicide is a terrible deed, but the Prophet’s connection and devotion to Allah was at such a high level, even if he was overcome by sadness and grief, it would not weaken him. Look at the example of Prophet Job (عليه السلام), for instance, who was struck with calamities but maintained his patience and faith in Allah.
3) When faced with such narrations, found in the book which is sahih, the Sunnis obviously face a bit of embarrassment. The main explanation they can muster is claiming the phrase “thrown himself of high mountains” was merely a metaphor emphasizing sadness, and was not referring to literally killing oneself.
However, not only does this not correlate with Arabic literature (in fact, it was a non-Arabic speaker who even concocted this rebuttal), but in that case why would the Prophet go to the top of the mountain in the first place, only for Jibrael to placate him? If I say for instance, “I am so hungry I could eat a horse”, which is a famous phrase, it would not make any sense for me to then go to a stable, would it?
In conclusion, the Prophet did not contemplate suicide nor was he confused when he first received the revelation. It is up to the Sunnis whether they would like to continue believing and accepting such things.
We Shias, believe Prophet(s.a.w) was free from all types of sin and was at the pinnacle of piety throughout his life.