Musnad Ahmad 1:28

Hammad ibn Usamah narrated to us, he said: Isma'il informed us, from Qays, who said: Abu Bakr stood up, praised Allah and extolled Him, then said: "O people, you recite this verse: 'O you who have believed, upon you is [responsibility for] yourselves' [Al-Ma'idah: 105]—until he reached the end of the verse. Verily, when people see the oppressor and do not take hold of his hands, Allah is about to encompass them with His punishment. Verily, I heard the Messenger of Allah, peace and blessings of Allah be upon him, saying: 'Indeed, the people...'" And he said another time: "And we heard the Messenger of Allah, peace and blessings of Allah be upon him..."