Hadith: Jibrīl came to the Messenger of Allah (may Allah's peace and blessings be upon him) while he was playing with his playmates. He took hold of him, laid him on the ground, split open his chest, took the heart out and then extracted a blood clot out of it and said: That was the devil's share in you

عن أنس بن مالك رضي الله عنه أن رسول الله صلى الله عليه وسلم أتَاه جبريل صلى الله عليه وسلم وهو يَلْعَب مع الغِلمان، فأخَذَه فصَرَعه، فشقَّ عن قلبه، فاستَخْرَج القلب، فاستخرج منه عَلَقة، فقال: هذا حَظُّ الشيطان منك، ثم غَسَله في طَسْت مِن ذَهَب بماء زمزم، ثم لَأَمَهُ، ثم أعاده في مكانه، وجاء الغِلْمان يَسْعَون إلى أُمِّه -يعني ظِئْرِه- فقالوا: إن محمدًا قد قُتِل، فاستَقْبَلُوه وهو مُنْتَقِعُ اللَّوْن، قال أنس: «وقد كنتُ أَرَى أثر ذلك المِخيط في صدره».
[صحيح] - [رواه مسلم]

Anas ibn Mālik (may Allah be pleased with him) reported: Jibrīl came to the Messenger of Allah (may Allah's peace and blessings be upon him) while he was playing with his playmates. He took hold of him, laid him on the ground, split open his chest, took the heart out and then extracted a blood clot out of it and said: "That was the devil's share in you." Then he washed it with Zamzam water in a golden basin and then joined the wounded parts together after he restored the heart to its place. The boys came running to his mother, i.e. his wet nurse, and said: "Muhammad has been killed." They rushed to him and found his color was changed. Anas said: "I used to see the scar of this stitching on his chest."
[Authentic hadith] - [Narrated by Muslim]

Explanation

Jibrīl came to the Prophet (may Allah's peace and blessings be upon him) when he was a little child playing with his mates. He put him on his back on the ground, slit his heart and took out of it a clot of thick blood, which is the source of evils and sins in the heart. Jibrīl said that this would have been the devil's share in the Prophet if such a clot of blood had remained in him. Then, he washed his heart with Zamzam water in a golden basin. Then he fixed the split, put the heart back in its place, and stitched the wound. Children who were playing with the Prophet (may Allah's peace and blessings be upon him) rushed to his wet nurse Halīmah and told her that Muhammad was killed. They went to his place and found him pale. Anas, who narrated this Hadīth, did not witness the incident himself. Yet, he must have heard it from a trustworthy Companion or through continuous chain of narrators. Anas said that he used to see the scar of stitching visible on the Prophet's chest. This is another proof that splitting the chest was physical, not spiritual. One should take this Hadīth and similar ones at face value without interpreting them metaphorically. There is no need for a metaphorical interpretation, for the Hadīth is a report from the truthful Messenger about the power of Allah, the Omnipotent.