Albert Barnes Commentary Psalms 105:10

"And confirmed the same unto Jacob for a statute, To Israel for an everlasting covenant," — Psalms 105:10 (ASV)

And confirmed the same to Jacob - literally, “caused it to stand;” that is, He made it fast or secure. He renewed it, commanding the same things, making the same promises, and pledging Himself for its fulfillment in the same manner (Genesis 28:10–15).

For a law - For an established or settled ordinance, for a rule by which future things were to be regulated: that is, they would occur according to that promise and be conformed to it. It was, as it were, a rule which God prescribed for Himself in regard to His own future conduct.

And to Israel... - Another name for Jacob (Genesis 32:28).