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).