Sahih al-Bukhari 6383
Narrated Abu Musa:
The Prophet (ﷺ) asked for some water and performed the ablution, and then raised his hands (towards the 
sky) and said, "O Allah! Forgive `Ubaid Abi 'Amir." I saw the whiteness of his armpits (while he was 
raising his hands) and he added, "O Allah! Upgrade him over many of Your human creatures on the 
Day of Resurrection."
حَدَّثَنَا مُحَمَّدُ بْنُ الْعَلاَءِ، حَدَّثَنَا أَبُو أُسَامَةَ، عَنْ بُرَيْدِ بْنِ عَبْدِ اللَّهِ، عَنْ أَبِي بُرْدَةَ، عَنْ أَبِي مُوسَى، قَالَ دَعَا النَّبِيُّ صلى الله عليه وسلم بِمَاءٍ فَتَوَضَّأَ، ثُمَّ رَفَعَ يَدَيْهِ فَقَالَ ‏"‏ اللَّهُمَّ اغْفِرْ لِعُبَيْدٍ أَبِي عَامِرٍ ‏"‏‏.‏ وَرَأَيْتُ بَيَاضَ إِبْطَيْهِ فَقَالَ ‏"‏ اللَّهُمَّ اجْعَلْهُ يَوْمَ الْقِيَامَةِ فَوْقَ كَثِيرٍ مِنْ خَلْقِكَ مِنَ النَّاسِ ‏"‏‏.‏