The Book Pertaining to the Merits of the Companions (Allah Be Pleased With Them) of the Holy Prophet (May Peace Be Upon Him) (Kitab Al-Fada'il Al-Sahabah)
Muslim :: Book 31 : Hadith 5928
'Abdullah b. Shaddad reported that he heard 'Allahs saying: Allah's Messenger (may peace be upon him) did not gather his parents except in case of Sa'd b. Malik that he said to him on the Day of Ubud: Shoot an arrow, may my father and mother be taken as ransom for you.