Musnad Ahmad 1156:86

Hassan narrated to us, Ibn Lahi'ah narrated to us, he said: Ja'far ibn Rabi'ah narrated to us, from Abdullah ibn Abd al-Rahman ibn Abi Sa'sa'ah, from Umm Hakim al-Sulaymiyyah, from Umm Salamah, the wife of the Prophet, may God bless him and grant him peace, that the Messenger of God, may God bless him and grant him peace, said: "Whoever enters into Ihram from Bayt al-Maqdis, God will forgive him his past sins."