John Gill Commentary 1 Samuel 12:10

"And they cried unto Jehovah, and said, We have sinned, because we have forsaken Jehovah, and have served the Baalim and the Ashtaroth: but now deliver us out of the hand of our enemies, and we will serve thee." — 1 Samuel 12:10 (ASV)

And they cried unto the Lord
When in the hands of their enemies, and in bondage to them, and cruelly oppressed by them:

and said, we have sinned ;
the word for "said" is in the Cetib, or written text, singular, and in the Keri, or marginal reading, plural; and may signify, that everyone of them had a sense of their sin, and made acknowledgment of it; their confession was universal, as their sin was:

because we have forsaken the Lord ;
the Word of the Lord, as the Targum:

and have served Baalim and Ashtaroth; (See Gill on Judges 2:11), (See Gill on Judges 2:13).

but now deliver us out of the hand of our enemies, and we will serve
thee ;
they did not ask for a king to go before them, and fight their battles, as they did now, but applied to the Lord for deliverance, promising to serve him as their King and their God.