Musannaf Ibn Abi Shayba 36:412

Ubayd Allah ibn Musa narrated to us, he said: Usama ibn Zayd informed us, from al-Zuhri, from Abd al-Rahman ibn al-Azhar, who said: I saw the Messenger of Allah (may Allah bless him and grant him peace) in the year of the Conquest, while I was a young boy, asking for the house of Khalid ibn al-Walid. Then a drunkard was brought, and they struck him with what was in their hands; among them were those who struck with a whip, with a sandal, and with a stick, and the Prophet (may Allah bless him and grant him peace) threw dust upon him. When it was the time of Abu Bakr, a drunkard was brought, and he asked his companions: "How many did the Messenger of Allah (may Allah bless him and grant him peace) strike the one he struck?" So they determined it to be forty, and Abu Bakr struck [him] forty.