Musnad Abu Ya'la al-Mawsili 153:195

Ahmad ibn Ibrahim al-Nukri narrated to us, he said: Abu Dawud narrated to us, he said: Abd al-Rahman ibn Thabit ibn Thawban narrated to us, my father informed me, from Makhul, from Jubayr ibn Nufayr, from Ibn Umar, that the Messenger of Allah (may Allah bless him and grant him peace) said: "Indeed, Allah accepts the repentance of His servant as long as he does not reach the death rattle."