John Gill Commentary 2 Kings 3:16

"And he said, Thus saith Jehovah, Make this valley full of trenches." — 2 Kings 3:16 (ASV)

And he said, thus says the Lord, make this valley full of ditches . ] In which the allied army lay encamped, that they might be ready to receive large quantities of water, sufficient for the whole army and cattle, when it came.