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

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.