Sunnan Abu Dawud Collection: ::Book Number 10:: Hadith # 1854
Narrated Ka'b ibn Ujrah: The Apostle of Allah (peace_be_upon_him) came upon him (during their stay) at al-Hudaybiyyah. He then narrated the rest of the tradition. This version adds: "He asked: Do you have a sacrificial animal? He replied: No. He then said: Fast three days or give three sa's of dates to six poor people, giving one sa' to every two persons."