Does movement in prayer invalidate it?

Question:
This is a request for guidance and advice for the one who prays who is preoccupied during the prayer with adjusting his clothes several times, or looking at the clock, or who has a lack of khushu' (humility) in his prayer.

Answer:
This is a defect in the prayer. The Muslim should be humble and his limbs should be at rest. There is no harm in slight movement out of necessity, such as adjusting a garment or a turban or the like, out of necessity; there is no harm in that. However, fiddling around and excessive movement without necessity, this diminishes the prayer and disrupts it, and it may invalidate it if it continues and he becomes preoccupied with it to the extent that he is not focused on his prayer. Yes. May Allah reward you.