Musnad Ahmad 918:7

Abdullah ibn al-Harith narrated to us, al-Aslami—meaning Abdullah ibn Amir—narrated to me, from Imran ibn Abi Anas, from Sahl ibn Sa’d, from Ubayy ibn Ka’b: That the Messenger of Allah, peace and blessings of Allah be upon him, was asked about the mosque which was founded on righteousness (taqwa). He said: "It is my mosque."