John Gill Commentary 1 Samuel 12:13

"Now therefore behold the king whom ye have chosen, and whom ye have asked for: and, behold, Jehovah hath set a king over you." — 1 Samuel 12:13 (ASV)

Now therefore behold the king whom you have chosen, and whom you
have desired
For though God chose their king for them, it was at their request; they chose to have a king, and desired one, and they approved of and consented to, and confirmed the choice he had made, and so it was in effect their own:

and, behold, the Lord has set a king over you ;
he gratified them in their desires; though he did not suffer them to make themselves a king, he suffered them to have one, and he gave them one; this power he reserved to himself of setting up and pulling down kings at his pleasure.