سنن ابن ماجه

It was narrated from 'Abdul-Jabbar bin Wa'il that : his father said: "I prayed with the Prophet (ﷺ) and a man said: 'Alhamdu lillahi hamdan kathiran tayyiban mubarakan fihi (Praise is to Allah, much, good and blessed praise).' When the Prophet (ﷺ) finished praying, he said: 'Who said that?' The man said: 'It was me, but I did not mean anything but good.' He said: 'The gates of heaven were opened because of it and nothing prevented it from reaching the Throne.'"