John Gill Commentary 2 Kings 2:18

"And they came back to him, while he tarried at Jericho; and he said unto them, Did I not say unto you, Go not?" — 2 Kings 2:18 (ASV)

And when they came again to him, for he waited at Jericho ,
&c.] Waiting their return to hear the report they made: which when they had,

he said to them, did I not say to you, go not ?
assuring them it would be fruitless, and to no purpose; though this search of theirs served both to confirm the assumption of Elijah, and the truth of Elisha being a prophet of the Lord.