Musnad Abu Ya'la al-Mawsili 154:87

Ali ibn al-Ja'd narrated to us, Ibn Thawban narrated to us, from his father, from Makhul, from Jubayr ibn Nufayr, from Abdullah ibn Umar, from the Prophet, peace and blessings of Allah be upon him, who said: "Indeed, Allah accepts the repentance of the servant as long as he does not reach the state of *ghargharah* (the death rattle)."