Musnad Abu Ya'la al-Mawsili 1:133

Abu Khaythama and Ishaq ibn Isma'il narrated to us, they said: Sufyan narrated to us, from 'Amr ibn Dinar, from Yahya ibn Ja'dah, who said: Abu Bakr al-Siddiq said while he was on the pulpit, and he wept: I heard the Messenger of Allah (may Allah bless him and grant him peace) in the summer of the first year, while the covenant was recent, saying: "Ask Allah for certainty and well-being."