John Calvin Reformed @genevareformer

He at length adds, And I have this day declared it to you Here he sets forth his own fidelity, not for the sake of boasting, but that their impiety might be reproved, who at length despised the oracle of God, which they had boasted that they would obey.

Matthew Henry Presbyterian @wholebiblehenry

We have here the answer which Jeremiah was sent to deliver to those who employed him to ask counsel of God. I. It did not come immediately, not till ten days after, Jer 42:7. They were thus long held in suspense, perhaps, to punish them for their hypocrisy or to show that Jeremiah did not speak of himself, nor what he would, for he could...

Commenting on Jeremiah 42:7-22

John Gill Reformed Baptist @doctorgill

Now therefore know certainly,.... Or, "in knowing know" (d); they might assure themselves of this, that it would certainly come to pass, and most justly and deservedly; since it was at their own request the prophet sought the mind of the Lord for them, and had faithfully related it to them, and they had promised to observe it; wherefore, should they go into Egypt, as...