Hadith 4407
Sayyiduna Abdullah bin Mas’ud (may Allah be pleased with him) narrates: The Prophet Muhammad (peace and blessings be upon him) said: “By the One besides whom there is no deity, it is not permissible to kill any person who testifies that there is no god but Allah and that I am the Messenger of Allah, except in three cases: a person who abandons Islam and separates from the (Muslim) community, a married adulterer, and a person who is killed in retaliation for (murdering) another.” A’mash states: I narrated this hadith to Ibrahim, so he narrated to me a similar narration from Aswad, from Sayyidah Aisha (may Allah be pleased with her).
Hadith 4408
Sayyiduna Abdullah bin Mas'ud (may Allah be pleased with him) narrates: The Noble Prophet (peace and blessings be upon him) said: "It is not permissible to shed the blood of a person who testifies that there is no deity except Allah and that I am the Messenger of Allah, except in three cases: a married adulterer, a life for a life, and a person who abandons his religion (i.e., Islam) and separates from the community (i.e., such a person is to be killed)."