chapter 18 of 22 (46 verses.)

1st Kings 18:40

So EliJah {JAH-Is-El} says to [Israel's leaders], “Capture the prophets of Baal {Demon-Master}.
Don't let one of them escape!”
[So the soldiers] arrest [the child-sacrificing demon-prophets].
Then EliJah brings the [satanists] down to the Kishon {Hard-Ground} brook.
There [EliJah does or says something that] causes [some human or spirit force] to slaughter all [the false prophets]!

Note: Again, YAH did not command EliJah to kill those people.
Yet YAH was probably happy to see them dead.
ַוִיּ ְשׁ ָח ֵטם (u·ishcht·m) is a Hebrew idiom, meaning EliJah does something that leads other people or supernatural forces to kill the false prophets.
(Maybe EliJah pointed out to some Israeli soldiers that as long as those evil religionites were alive, it wouldn't rain.) Perhaps EliJah praised YAH, triggering a supernatural force that killed the false prophets.
At any rate, EliJah does not himself kill anyone.

Complete Jewish Bible (Sacred Name Version)	CJB-SN	Eliyahu said to them, "Seize the prophets of Ba‘al! Don’t let one of them escape!" They seized them; and Eliyahu brought them down to Vadi Kishon and killed them there.
New International Version (Sacred Name)	NIV-SR	Then Elijah commanded them, 'Seize the prophets of Baal. Don't let anyone get away!' They seized them, and Elijah had them brought down to the Kishon Valley and slaughtered there.
New International Readers Version (Sacred Name)	NIRV-SN	Then Elijah commanded them, 'Grab hold of the prophets of Baal. Don't let a single one of them get away!' So they grabbed them. Elijah had them brought down to the Kishon Valley. There he had them put to death.
New Living Translation (Sacred Name Version)	NLT-SN	Then Elijah commanded, 'Seize all the prophets of Baal. Don't let a single one escape!' So the people seized them all, and Elijah took them down to the Kishon Valley and killed them there.
New Revised Standard (Sacred Name Edition)	NRSV-SN	Elijah said to them, "Seize the prophets of Baal; do not let one of them escape." Then they seized them; and Elijah brought them down to the Wadi Kishon, and killed them there.
The Message (Sacred Name Version)	MSG-SN	Elijah told them, 'Grab the Baal prophets! Don't let one get away!' They grabbed them. Elijah had them taken down to the Brook Kishon and they massacred the lot.
Good News Translation (Sacred Name)	GNT-SN	Elijah ordered, "Seize the prophets of Baal; don't let any of them get away!" The people seized them all, and Elijah led them down to Kishon Brook and killed them.
New American Standard (Sacred Name Bible)	NASB-SN	Then Elijah said to them, 'Seize the prophets of Baal; do not let one of them escape.' So they seized them; and Elijah brought them down to the brook Kishon, and slew them there.
King James Version (unedited)	KJV	And Elijah said unto them, Take the prophets of Baal; let not one of them escape. And they took them: and Elijah brought them down to the brook Kishon, and slew them there.