Hadith 961:30
'Abd al-Razzaq narrated to us, Ma'mar informed us, from Ayyub, from Humayd ibn Hilal al-'Adawi, from Abu Burdah, who said: Mu'adh ibn Jabal arrived to Abu Musa in Yemen, and there was a man with him. He said: "What is this?" He replied: "A man who was a Jew, then he became a Muslim, then he returned to Judaism, and we have been urging him to return to Islam for—I think he said—two months." He said: "By Allah, I will not sit down until you strike his neck." So his neck was struck. He then said: "Allah and His Messenger have decreed: 'Whoever returns from his religion, kill him,'" or he said: "'Whoever changes his religion, kill him.'"
حدثنا عبد الرزاق، أخبرنا معمر، عن أيوب، عن حميد بن هلال العدوي، عن أبي بردة، قال: قدم على أبي موسى معاذ بن جبل، باليمن، فإذا رجل عنده، قال: ما هذا؟ قال: رجل كان يهوديا، فأسلم، ثم تهود، ونحن نريده على الإسلام منذ، قال: أحسبه، شهرين. فقال: والله لا أقعد حتى تضربوا عنقه. فضربت عنقه، فقال: قضى الله ورسوله: " أن من رجع عن دينه فاقتلوه " أو قال: " من بدل دينه فاقتلوه "