Anas bin Malik reported,

Anas reported that Jibreel came to the Messenger of Allah ﷺ while he was playing with the other boys. He took hold of him, threw him to the ground, and split open his chest. He extracted the heart, removed a clot from it, and said, "This is the share of Satan in you." Then he washed it in a golden basin with Zamzam water, sealed it back up, and returned it to its place.The boys came running to his mother, meaning his wet nurse, and cried, "Muhammad has been killed!" They went out to meet him and found him pale in color.Anas said, "I used to see the trace of that stitching on his chest."

Azami 8511

Sahih

عن أنس

أن رسول الله ﷺ هل أتاه جبريل، وهو يلعب مع الغلمان. فأخذه فصرعه فشق عن قلبه. فاستخرج القلب، فاستخرج منه علقة فقال: هذا خط الشيطان منك، ثم غسله في طست من ذهب بماء زمزم، ثم لأمه، ثم أعاده في مكانه. وجاء الغلمان يسعون إلى أمه (يعني ظئره) فقالوا: إن محمدا قد قتل، فاستقبلوه وهو منتقع اللون. قال أنس: وقد كنت أرى أثر ذلك المخيط في صدره.

الأعظمي 8511صحيح
Contents
Reference
Commentary
Ayat
Collection
Jami al-Kamil
Book
Biography of the Prophet ﷺ
Section
Miracle of the splitting of the chest while he was a boy
Numbering
Jami al-Kamil 8511 (2nd edition)
Azami 8511