John Gill Commentary 2 Kings 10:24

"And they went in to offer sacrifices and burnt-offerings. Now Jehu had appointed him fourscore men without, and said, If any of the men whom I bring into your hands escape, [he that letteth him go], his life shall be for the life of him." — 2 Kings 10:24 (ASV)

And when they went in to offer sacrifices and burnt offerings ,
&c.] To Baal, all things being ready for them:

Jehu appointed eighty men without ;
without the temple of Baal, at the several doors and avenues of it:

and said, if any of the men whom I have brought into your hands escape,
he that letteth him go, his life shall be for the life of him ;
should be put to death for it in his room; the life of a watchman set to guard should go for the life of one that escaped.