Sunan Abi Dawud

Narrated Abdullah ibn Mas'ud: The Prophet (ﷺ) said: When one of you bows, he should say three time,:""Glory be to my mighty Lord,"" and when he prostrates, he should say: ""Glory be to my most high Lord"" three times. This is the minimum number. Abu Dawud said: The chain of this tradition is broken. The narrator 'Awn did not see 'Abd Allah (b. Mas'ud)