Abu Dawud Book 33, Hadith Number 4474.
Narated By AbdurRahman ibn Azhar : I saw the Apostle of Allah (PBUH) on the morning of the conquest of Mecca when I was a young boy. He was walking among the people, seeking the camp of Khalid ibn al-Walid. A man who had drunk wine was brought (before him) and he ordered them (to beat him). So they beat him with what they had in their hands. Some struck him with whips, some with sticks and some with sandals. The Apostle of Allah (PBUH) threw some dust on his face.
When a man who had drunk wine was brought before AbuBakr, he asked them (i.e. the people) about the number of beatings which they gave him. They numbered it forty. So AbuBakr gave him forty lashes.
When Umar came to power, Khalid ibn al-Walid wrote to him: The people have become addicted to drinking wine and they look down upon the prescribed punishment and its penalty.
He said: They are with you, ask them. The immigrants who embraced Islam in the beginning were with him. He asked them and they agreed on the fact that (a drunkard) should be given eighty lashes.
Ali said: When a man drinks wine, he tells lies. I, therefore, think that he should be prescribed punishment that is prescribed for telling lies..