John Gill Commentary Exodus 4:31

"And the people believed: and when they heard that Jehovah had visited the children of Israel, and that he had seen their affliction, then they bowed their heads and worshipped." — Exodus 4:31 (ASV)

And the people believed
That Moses was sent of God, and would be the deliverer of them:

and when they heard that the Lord had visited the children of Israel ;
in a way of grace and mercy, by raising such a redeemer and deliverer in the midst of them:

and that he had looked upon their affliction ;
with an eye of pity and compassion:

then they bowed their heads, and worshipped ;
adoring the goodness of God, and expressing their thankfulness for the notice he took of them, and signifying their readiness to obey all instructions and directions that should be given them.