Musnad Ahmad 517:0

Narrated to us by Yahya ibn Sa’id, from Sufyan, who said: Narrated to me Abu Ishaq, from ‘Amr ibn Maymun, from ‘Abdullah ibn Mas’ud—and he mentioned the name of Jabir—who said: The Messenger of Allah (ﷺ) said: "The blood of a Muslim man who testifies that there is no god but Allah and that I am the Messenger of Allah is not lawful, except for one of three: the married adulterer, a life for a life, and the one who abandons his religion and separates from the community."