Musnad Abu Ya'la al-Mawsili 108:18

Abu al-Rabi' narrated to us, Ismail bin Zakariya narrated to us, from al-Mu'alla, from Abdullah bin Muhammad bin Aqil, from Jabir: That the Messenger of Allah (may Allah bless him and grant him peace) asked a man who had apostatized from Islam to repent four times.