Military Expeditions led by the Prophet (pbuh) (Al-Maghaazi)
Bukhari :: Book 5 :: Volume 59 :: Hadith 387
Narrated Ibn Al Musaiyab:
Sad bin Abi Waqqas said, "Allah's Apostle mentioned both his father and mother for me on the day of the battle of Uhud." He meant when the Prophet said (to Sad) while the latter was fighting. "Let my father and mother be sacrificed for you!"