Imam Muslim related that Anas (may Allah be pleased with him) narrated,
Gibrael came to the Messenger of Allah (peace be upon him) when he was playing with two young boys. He (Gibrael) took him and placed the Messenger of Allah (peace be upon him) on the ground. He then opened the chest of the Messenger of Allah (peace be upon him), took out his heart, and then took out a lump from it. He said, ‘This was the measure of Satan inside you.’ After that, he washed it [the heart] with zamzam water in a golden container, joined it together again, and placed it in its proper place. The two young boys returned to his mother [through breastfeeding] and said, ‘Muhammad has been killed.’ They later meet him and noticed that the colour of his face had changed. We [the Companions] saw the effect of the stitches on his chest related by Muslim
This story is known among scholars of the biography of Mohammed (peace be upon him) as ‘the splitting open of the chest’. The important point we learn from this hadith is that Gibrael (peace be upon him), after he took the lump from the heart of the Messenger of Allah (peace be upon him), said, this is your allotment from Satan, which means that Allah purified the chest of the Messenger of Allah (peace be upon him) from any whisperings of Satan. Allah referred to this incident in His book:
Have we not spilt open your chest, and removed the burden from you that was weighing down on your back Surah Ash-Sharh: 1 – 3
And in this way the Messenger of Allah (peace be upon him) was purified
Allah (Glorified is He) says:
And We have raised the esteem by which you are remembered Surah Ash-Sharh: 4
And He (Glorified is He) also purified his (peace be upon him) manners, as He says:
And truly, you have sublime morals Surat Al-Qalam: 4
Just as He purified his (peace be upon him) mind, as Allah (Glorified is He) says,
And your companion is neither astray or misguided Surah An-Najm: 2
He purified him (peace be upon him) more by making him be truthful
And he does not say anything from [his own] desire Surah An-Najm: 3
And He purified his (peace be upon him) sight, as Allah says,
And his sight did not swerve or go wrong Surah An-Najm: 17
Moreover, He purified his (peace be upon him) patience:
Merciful and compassionate with the believers Surah At-Tawba: 128
And also his (peace be upon him) knowledge:
He was taught by One Mighty in power Surat An-Najm: 5
