The Messenger of Allah ﷺ said to Abu Musa, "If only you had seen me last night as I listened to your recitation. You have been granted one of the flutes of the family of Dawud."
قال رسول الله ﷺ لأبي موسى: لو رأيتني وأنا أستمع لقراءتك البارحة، لقد أوتيت مزمارا من مزامير آل داود.
Bukhari narrated it in the Virtues of the Quran (5048), and Muslim in the Prayer of Travelers (236:793), both through routes from Abu Burda, from Abu Musa, and he mentioned it. The wording given here is Muslim's.It has come in the Book of Allah, "And remember Our servant Dawud, the possessor of strength. Indeed, he was one who returned frequently to Allah. Indeed, We subjected the mountains to be with him, exalting Allah in the evening and morning. And the birds were assembled, all with him turning back." [Sad 38:17–19]What is meant by his saying "the flutes of the family of Dawud" is Dawud and his children. The mizmar is a type of instrument that is played while singing, though the term may also be used simply for a beautiful voice. Abu Musa Ashari did not play an instrument as Dawud did , though that was permissible in his law.