سنن النسائي

It was narrated that Rifa'ah bin Rafi said: "We were praying behind the Messenger of Allah (ﷺ) one day and when he raised his head from bowing he said: 'Sami Allahu liman hamidah (Allah hears the one who praises Him).' A man behind him said: 'Rabbana wa lakal-hamd, hamdan kathiran tayyiban mubarakan fih. (O our Lord, and to You be praise, much blessed and pure praise.)' When the Messenger of Allah (ﷺ) had finished, he said: "Who is the one who spoke just now?" The man said: 'I did, O Messenger of Allah.' The Messenger of Allah (ﷺ) said: 'I saw thirty-some angels rushing to see which of them would write it down first.'"