The Book of Prayer - Travellers
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا مُحَمَّدُ بْنُ بِشْرٍ، حَدَّثَنَا سَعِيدُ بْنُ أَبِي عَرُوبَةَ، حَدَّثَنَا قَتَادَةُ، عَنْ زُرَارَةَ بْنِ أَوْفَى، عَنْ سَعْدِ بْنِ هِشَامٍ، أَنَّهُ قَالَ انْطَلَقْتُ إِلَى عَبْدِ اللَّهِ بْنِ عَبَّاسٍ فَسَأَلْتُهُ عَنِ الْوِتْرِ . وَسَاقَ الْحَدِيثَ بِقِصَّتِهِ وَقَالَ فِيهِ قَالَتْ مَنْ هِشَامٌ قُلْتُ ابْنُ عَامِرٍ . قَالَتْ نِعْمَ الْمَرْءُ كَانَ عَامِرٌ أُصِيبَ يَوْمَ أُحُدٍ .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
From Sahih Muslim, whose reports the scholars accept as authentic.