Musannaf Ibn Abi Shayba 21:211

Abu Usamah and Ibn Numayr narrated to us, from Hisham ibn Urwah, from Abbad ibn Abdullah ibn al-Zubayr, who said: I heard Aisha saying: I heard the Messenger of Allah, may Allah bless him and grant him peace, while he was leaning against my back, [saying]: "O Allah, forgive me, and have mercy upon me, and join me with the Highest Companion."