Sahih Bukhari
Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Volume: 005 / Book Number: 059 / Hadith Number: 489
Narrated Abu Qilaba:
that Thabit bin Ad-Dahhak had informed him that he was one of those who had given the Pledge of allegiance (of Al-Hudaibiya) beneath the Tree.