Sahih Bukhari
Judgments (Ahkaam)
Volume: 009 / Book Number: 089 / Hadith Number: 328
Narrated Tariq bin Shihab:
Abu Bakr said to the delegate of Buzakha. "Follow the tails of the camels till Allah shows the Caliph (successor) of His Prophet and Al-Muhajirin (emigrants) something because of which you may excuse yourselves "