Sahih Muslim
The Book of Prayers (Kitab Al-Salat)
Book Number: 004 / Hadith Number: 1625
Sa'd b. Hisham reported: I went to 'Abdullah b. 'Abbas and asked him about the Witr prayer, and the rest of the hadith is the same as recorded in this event. She (Hadrat 'A'isha) said: Who is that Hisham? I said: Son of 'Amir. She said: What a fine man 'Amir was! He died as a martyr in the Battle of Uhud.