Amir bin Sa'd narrates from his father, Sayyiduna Sa'd (may Allah be pleased with him), that the Prophet (peace and blessings be upon him) mentioned both his parents for him (that is, he used the words of ransoming with both father and mother). He said: There was a man from among the polytheists who was burning the Muslims, so the Prophet (peace and blessings be upon him) said to Sa'd: "Shoot, may my father and mother be your ransom." Sa'd said: So I drew an arrow that had no head and struck him in his side; he fell and his private parts were exposed, and the Prophet (peace and blessings be upon him) laughed so much that I saw his (peace and blessings be upon him) molar teeth.
Hadith Referenceالمعجم الكبير للطبراني / العشرة / 313