Musnad Abu Ya'la al-Mawsili 151:46

Abu Bakr narrated to us, Mu'awiyah ibn Hisham narrated to us, from Sharik, from 'Uthman ibn Abi Zur'ah, from Abu Sadiq, from 'Abd al-Rahman ibn Yazid, from 'Abdullah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "For Paradise, there are eight gates: seven are closed, and one gate is open for repentance until the sun rises from its direction."