Sahih al-Bukhari 6359
Sahih al-Bukhari · Book 80: Invocations · Can one send Salat on anybody other than the Prophet (saws)
Narrated Ibn Abi `Aufa:
حَدَّثَنَا سُلَيْمَانُ بْنُ حَرْبٍ ، حَدَّثَنَا شُعْبَةُ ، عَنْ عَمْرِو بْنِ مُرَّةَ ، عَنِ ابْنِ أَبِي أَوْفَى ، قَالَ كَانَ إِذَا أَتَى رَجُلٌ النَّبِيَّ صلى الله عليه وسلم بِصَدَقَتِهِ قَالَ " اللَّهُمَّ صَلِّ عَلَيْهِ" فَأَتَاهُ أَبِي بِصَدَقَتِهِ فَقَالَ " اللَّهُمَّ صَلِّ عَلَى آلِ أَبِي أَوْفَى"
Whenever somebody brought alms to the Prophet (ﷺ) the used to say, "Allahumma Salli 'Alaihi (O Allah! Send Your Salat (Grace and Honor) on him)." Once when my father brought his alms to him, he said, "O Allah! Send Your Salat (Grace and Honor) on the family of Abi `Aufa."