Why does the Lord promise to tell the people hidden things they have not known, if they call on him?
The Lord is described as the Lord who made the earth, the Lord who formed and established it – the Lord is his name.
This refers back to the way Jeremiah describes the Lord in Jeremiah 32:17. The Lord also affirms this description of himself in Jeremiah 32:27. He is indeed the God who created everything and nothing is too hard for him. The Lord is his name.
Any listener who is able to truly grasp who it is that is speaking will know how reliable his announcements are1.
This same Lord now invites Jeremiah and the people of Judah to call on him for answers regarding hidden things that you have not known.
If they ask, the Lord will reveal unknown things about the future that will sustain them as they face the Babylonian invasion and exile2.
3 Invoque-moi, et je te répondrai; Je t'annoncerai de grandes choses, des choses cachées, Que tu ne connais pas.