Commentary on the Bible, by Adam Clarke, [1831], at sacred-texts.com
This and the four following chapters contain a distinct account of what passed in the land of Judah from the taking of Jerusalem to the retreat of the remnant of the people to Egypt; together with the prophecies of Jeremiah concerning that place, whither he himself accompanied them. In this chapter we have an account of the enlargement of Jeremiah by Nebuzar-adan, the captain of the guard, who advises him to put himself under the jurisdiction of Gedaliah, the son of Ahikam, whom the king of Babylon had made governor over the land of Judea, Jer 40:1-5. The prophet and many of the dispersed Jews repair to Gedaliah, Jer 40:6-12. Johanan acquaints the governor of a conspiracy against him, but is not believed, Jer 40:13-16.
The word that came to Jeremiah - This and the four following chapters contain a particular account of what passed in the land of Judea from the taking of the city to the retreat of the people into Egypt, and the prophecies of Jeremiah concerning them there.
Had let him go from Ramah - This has embarrassed most of the commentators. Dr. Blayney has thrown much light upon it by his translation and note: -
"The word that came to Jeremiah from Jehovah, after that Nebu-Zaradan captain of the guards had taken him, and let him go from Ramah: for he had been bound with chains among all the captives of Jerusalem and Judah, who were carried away captive to Babylon."
"Had Taken Him, and Let Him Go. - Most interpreters have understood בקחתו אתו bekachto otho of Nebuchadnezzar's having first taken Jeremiah as a captive unto Ramah. But if the order of the sentence be well observed, as well as the more common use of the verb לקח lakach, it will, I think, rather appear that those words relate to his taking or having him brought to him, in order to give him his discharge."
The Lord thy God hath pronounced - I know that thou art a true prophet, for what thou hast predicted from thy God is come to pass.
Come; and I will look well unto thee - Thou art now at full liberty to do as thou pleasest; either to come to Babylon or to stay in thy own land.
Go back also to Gedaliah - If thou wilt stay in thy own land, thou hadst best put thyself under the protection of thy countryman Gedaliah, whom the King of Babylon has made governor of the land.
Ishmael the son of Nethaniah - This is he who afterwards murdered Gedaliah. He had been employed to do this by Baalis, king of the Ammonites, with whom he appears to have taken refuge during the siege. See Jer 40:14.
But Gedaliah the son of Ahikam believed then not - The account given of this man proves him to have been a person of uncommon greatness of soul. Conscious of his own integrity and benevolence, he took the portrait of others from his own mind; and therefore believed evil of no man, because he felt none towards any in his own breast. He may be reproached for being too credulous and confident: but any thing of this kind that may be justly charged against him serves only to show the greatness of his mind. A little soul is ever suspicious, and ready to believe the worst of every person and thing. A great mind acts always on the contrary.
Thou shalt not do this thing - He cannot be so base.
Thou speakest falsely of Ishmael - He thought it quite possible that the man who was capable of becoming an assassin was capable of telling a lie; and therefore he would not credit what he said. Had he been a little more distrustful, he would have saved his own life. The next chapter shows that Johanan's information was too true. So noble Gedaliah lost his life by not believing that evil of others of which he himself was incapable.