Jeremiah 23:26

Here God reproves the false prophets, and also promises to his people what was especially to be desired, — that he would cleanse his Church from such pollutions. He then shews that it was his purpose to take vengeance, because the false prophets had dared in such an impious and bold manner to abuse his sacred name. For it ever occurred to their minds, “How is it that God permits this? Is it because he cares not for the safety of his people? or does it give him any delight when he sees truth mingled with falsehood, and light with darkness?” Hence God here shews that he for a time bore with that sacrilegious audacity which the false prophets practiced, but that he did not so connive at it as not at length to punish them.

How long? he says, which is the same as though he had said, “It shall not be perpetual; though I may delay, yet they shall know that they have with extreme perverseness abused my forbearance.” And he also enhances their crime by saying, How long shall it be in the heart of the prophets to prophesy falsehood? By this way of speaking he intimates, that they erred not through ignorance, as many do, who through want of knowledge bring forth what they do not understand; but God here complains that these prophets, as it were designedly, rose up to suppress the truth. Then by heart is to be understood thought or purpose; as though he had said, that they designedly made a false pretense as to his name, that it was their settled purpose to deceive the people. (108)

He adds, that they were prophets of the deceit of their own heart. This deceit of the heart is put in opposition to true doctrine; and thus God intimates that whatever men bring forward from themselves is deceitful, for nothing can proceed from them but vanity. There is yet no doubt but that he condemns that foolish conceit, of which the false prophets proudly boasted, that they were alone wise, as the case is now under the Papacy; how arrogantly do unprincipled men prattle whenever they speak of their own figments? Nothing can be more silly, and yet they think that they surpass the angels in acuteness and in high speculations. Such was the arrogance displayed by the false prophets of old. But God declares that whatever men invent, and whatever they devise, which they have not received from his mouth, is only the deceit of the heart.

And this ought to be carefully noticed; for there are many plausible refinements, in which there is nothing solid, but they are mere trifles. If, then, at any time these vain thoughts seem pleasing to us, let us bear in mind what Jeremiah says here, that whatever proceeds not from God is the deceit of the heart; and further, that though the whole world applaud falsehoods and impostures, we ought yet to know that everything is a deceit which has not God himself as its author.

How long! — Is it in the heart of these prophets, To be prophesying falsehood, And prophesying the deceit of their own hearts?

To be “in the heart” is to be resolved, to form a purpose or determination. See Isaiah 63:4. It is the same, as though it was said, “Are these prophets resolved?” To be “in the heart” means also to delight in a thing. See Psalms 40:8. The meaning then may be, “Is it the delight of these prophets?” etc. But the first sense is the most suitable. “How long!” is an exclamation of wonder at their perseverance in their wicked course. They had been often warned, and yet they continued. Then follows a question, whether it was their settled purpose to persevere in prophesying falsely? — Ed.