Sahih Bukhari Volume 5, Book 59, Hadith Number 310.

Narrated By ‘Abdur-Rahman bin ‘Auf: “I had an agreement with Umaiya bin Khalaf (that he would look after my relatives and property in Mecca, and I would look after his relatives and property in Medina).” ‘Abdur-Rahman then mentioned the killing of Umaiya and his son on the day of Badr, and Bilal said, “Woe to me if Umaiya remains safe (i.e. alive).”