Musnad Abu Ya'la al-Mawsili 115:174

Abu Musa narrated to us, Mu'adh ibn Hisham narrated to us, my father narrated to me, from Qatadah, from Anas, that the Prophet of Allah (may Allah bless him and grant him peace) flogged for [drinking] wine with palm branches and sandals. Then Abu Bakr flogged forty [lashes]. When it was the time of Umar, and the people drew near to the rural areas and the villages, he said, "What do you see regarding the flogging for wine?" Abdur-Rahman ibn Awf said, "I see that you should make it like the lightest of the prescribed punishments." So Umar flogged eighty [lashes].