John Gill's Exposition of the Whole Bible
Jeremiah 40:16
But Gedaliah the son of Ahikam said unto Johanan the son of Kareah,.... In answer to his request, and the motion made by him:
thou shalt not do this thing; or, "do not do this thing" z; dissuading him from it, as being unlawful to take away a man's life in such a secret manner, without any legal process against him; though it seems to carry more in it, that he laid his commands upon him not to do it, and threatened him if he did:
for thou speakest falsely of Ishmael; or "a lie" a; a falsehood, a mere calumny; which was not using Johanan well, neither kindly nor genteelly, who had expressed such a concern for him, and for the public good. The event related in the following chapter shows that the information was good, and that it was no lie or calumny that was told; and it would have been well for Gedaliah, and the people of the Jews, had he given credit to it; but the time was not come for the Jewish commonwealth to be restored; and things were thus suffered to be, for the further punishment of the sins of that people.
z אל תעש את הדבר "noli facere hoc verbum", V. L. "ne facias verbum hoc", Pagninus, Montanus, Schmidt. a שקר "mendacium", Schmidt; "falsum", Pagninus, Montanus.