Musnad Abu Ya'la al-Mawsili 148:21

Narrated to us Ibn Jami‘ Muhammad Abu ‘Abd Allah ibn Abi Kamil, narrated to us al-Hasan ibn Musa, narrated to us al-Layth ibn Sa‘d, narrated to us Bukayr ibn ‘Abd Allah, from Muhammad ibn ‘Abd Allah ibn Abi Sulaym, from Anas ibn Malik, who said: I prayed with the Prophet, may Allah bless him and grant him peace, at Mina two rak‘ahs, and with ‘Umar two rak‘ahs, and with ‘Uthman for a portion of his emirate.