Assalaamu alaykum. Please inform me how many times our beloved Prophet's, sallallaahu ʻalayhi wa sallam, chest was opened by angels. Some say twice and some say four times. Regards, Yusuf.

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger. 

The scholars held different views regarding the number of times when the chest of the Prophet, sallallaahu ʻalayhi wa sallam, was split open; some held that it happened twice, others said three times, some said four times, and yet others said otherwise.

Al-Haafith Ibn Hajar mentioned that the chest of the Prophet, sallallaahu ʻalayhi wa sallam, was split open four times and that the fifth was not authentically reported. He wrote:

“ʻIyaadh believed that the preponderant view is that the chest of the Prophet, sallallaahu ʻalayhi wa sallam, was split open for the first time when he was a young boy with his wet nurse Haleemah. As-Suhayli, on the other hand, held that it happened twice. This is the correct view in this regard and shall be substantiated when addressing the hadeeth of Shareek in the Book of Tawheed. In brief, the first splitting (of his chest) was to remove the clot that was said to be the portion of the Devil in his heart, and the second was to prepare him on that night to receive the divine revelation. At-Tayaalisi and Al-Haarith narrated in their hadeeth collections on the authority of ʻAa'ishah that the chest splitting happened the second time when Angel Jibreel (Gabriel) came to him with the divine revelation in the Hiraa' cave, and the reason for it is clear. It has also been reported that his chest was split when he was with ʻAbd Al-Muttalib and was about ten years old, as has been cited by Abu Nu'aym in his book Dalaa'il An-Nubuwwah. There is a narration about a fifth time, but it has not been authentically established." [Fat-h Al-Baari]

Allaah knows best.