Musnad Ahmad 26:878

Muhammad ibn Ja'far narrated to us, Shu'bah narrated to us, from Sulayman, who said: I heard 'Abdullah ibn Murrah narrating from Masruq, from 'Abdullah ibn Mas'ud, from the Prophet, peace and blessings of Allah be upon him, that he said: "The blood of a Muslim man is not lawful except by one of three: a life for a life, the married adulterer, and the one who abandons his religion, separating—or who separates—from the community."