John Calvin Reformed @genevareformer

Here the Prophet informs us, that Ishmael did not attain his wishes; for he had resolved to sell; as it were, the people to the king of Ammon, but he was intercepted in his course. But he says first, that John the son of Kareah had heard the report, and that he, together with other leaders, went to meet him in order to intercept him in his journey.

Matthew Henry Presbyterian @wholebiblehenry

It would have been well if Johanan, when he gave information to Gedaliah of Ishmael's treasonable design, though he could not obtain leave to kill Ishmael and to prevent it that way, yet had staid with Gedaliah; for he, and his captains, and their forces, might have been a life-guard to Gedaliah and a terror to Ishmael, and so have prevented the mischief without the...

Commenting on Jeremiah 41:11-18

John Gill Reformed Baptist @doctorgill

Then they took all the men,.... All the soldiers that were under their command; this they did at once, believing the report to be true, as they had reason to do; since they knew of Ishmael's designs, and had given notice and warning of them to Gedaliah, though he would not listen to them: and went to fight with Ishmael the son of Nethaniah: resolving...