Then Jeremiah the prophet said unto them, I have heard you; behold, I will pray unto the LORD your God according to your words; and it shall come to pass, that whatsoever thing the LORD shall answer you, I will declare it unto you; I will keep nothing back from you.

Then Jeremiah the prophet said unto them, I have heard you; behold, I will pray unto Jehovah your God according to your words; and it shall come to pass that whatsoever thing Jehovah shall answer you, I will declare it unto you; I will keep nothing back from you.

And Jeremias the prophet said to them: I have heard you: behold I will pray to the Lord your God according to your words: and whatsoever thing he shall answer me, I will declare it to you: and I will hide nothing from you.

And Jeremiah the prophet saith unto them, 'I have heard: lo, I am praying unto Jehovah your God according to your words, and it hath come to pass, the whole word that Jehovah answereth you, I declare to you, I do not withhold from you a word.'

Then Jeremiah the prophet said to them, I have given ear to you; see, I will make prayer to the Lord your God, as you have said; and it will be that, whatever the Lord may say in answer to you, I will give you word of it, keeping nothing back.

Then Jeremiah, the prophet, said to them: "I have listened. Behold, I will pray to the Lord your God according to your words. And whatever word he will respond to me, I will declare to you. And I will conceal nothing from you."

Et dixit illis Jeremias Propheta, Audivi, ecce ego orabo Jehovam Deum vestrum secundum sermones vestros, et erit quemcunque sermonem responderit Jehova vobis, annuntiabo vobis, non celabo a vobis quicquam.

In order to prepare them to obey, he testified that he would be a faithful messenger of God; for there is no doubt but that the Prophet, as we shall see, regarded them with suspicion. That he might therefore have them teachable and obedient to the answer expected from God, he said beforehand, that he would honestly and faithfully perform his office as a Prophet. I have heard, he says; here he shews how ready he was to attend, and how he neglected nothing conducive to their well being. I have heard, he says, Behold, I will pray according to your words There is no doubt but that he thus intimated that he wished well to them; and it might have rendered them more attentive to the oracle to know that the Prophet was influenced by love. Nor is there a doubt but that the Prophet testified his love towards them, that his doctrine might afterwards have more weight with them. By saying, Whatever your God will answer, he did not mean that the oracle would be revealed to all, for the words could not be otherwise explained than through the Prophet, who would openly make known to the whole people what he heard from God's mouth. But he says, that the answer would be given to them, because God would give the answer which was to be communicated to all, as it is said that God spoke to Moses, and also to all the people, for the doctrine was intended for all. Moses did not receive the law, nor its interpretation, in his own private character, but in order that the people might know what was right. So Jeremiah did here; the answer he received from God he made known as belonging in common to all the people. But in calling God their God, he did not mean to flatter them or to praise their piety, but to exhort them to surrender and devote themselves wholly to God, as though he had said, that they had to do with God, who had bound them to himself when he adopted them as his peculiar people, and then favored them with so many blessings. Since then God had made himself known to them, they could not reject his counsel with impunity, for there was no pretext of ignorance. We hence see what weight there is in this, your God; for Jeremiah reminded them that they could not with impunity trifle with God, for they were not their own, but had been chosen to be God's people, and on this condition, to be wholly subject to his authority. Then the sum of the whole is this, that the Prophet would faithfully convey to the Jews the answer God would give them; and he said this that his doctrine might have a greater authority among them. It now follows, --

Then Jeremiah the prophet said unto them, I have heard you,.... He took notice of what they said to him, and found himself disposed to comply with their request, and readily granted it:
behold, I will pray unto the Lord your God, according to your words; be an intercessor for them; use his interest with his God, and their God; and, on account of relation, might expect to be heard; whom he would humbly entreat to direct what they should do, as they desired:
and it shall come to pass, that whatsoever thing the Lord shall answer you, I will declare it unto you; I will keep nothing back from you; but faithfully make known the whole mind and will of God, just as it is delivered, be it in what way soever: and though it is not expressed, he might suggest that he had some doubt on his mind whether they would obey it or not; and that he expected they would be open and free in declaring themselves on that point; since he had so readily complied with their request, and was determined to act the faithful part to them; hence the following reply:

I have heard--that is, I accede to your request.
your God--Being His by adoption, ye are not your own, and are bound to whatever He wills (Exodus 19:5-6; 1-Corinthians 6:19-20).
answer you--that is, through me.
keep nothing back-- (1-Samuel 3:18; Acts 20:20).