John Gill Commentary Genesis 24:21

"And the man looked stedfastly on her, holding his peace, to know whether Jehovah had made his journey prosperous or not." — Genesis 24:21 (ASV)

And the man wondering at her At her affability and courteousness to a stranger; at her humility and condescension to take upon her such a service; at her readiness, diligence, and laboriousness in it; and the quick dispatch she made; and at her expressions and conduct being so exactly agreeable to the token he desired to have; and at the providence of God in bringing him to this place so seasonably; and at the damsel, that she should come just at this time, and every way answer his expectations and desires:

held his peace, to wit; or to know, to think and consider further with himself, whether, or "if" the Lord had made his journey prosperous or not; or if not; he was musing and saying within himself, surely God had made his journey prosperous; or if not, how was it that such strange surprising circumstances should occur? or what else must be done by him? or what methods must be taken for the future.