John Calvin Commentary Jeremiah 9:6

"Thy habitation is in the midst of deceit; through deceit they refuse to know me, saith Jehovah." — Jeremiah 9:6 (ASV)

The Prophet here introduces God as the speaker, so that the Jews might know that they were not dealing with a mortal man. For they might, according to their usual perverseness, have raised this objection: “You indeed severely condemn us and treat us reproachfully; but who has made you our judge?” Lest then they should think that the words which he had until now declared were the words of man, he interposes the authority of God. You, He says, dwell in the midst of a deceitful people.

But we must observe that this admonition to the Prophet was necessary for two reasons. For when God searches the minds and hearts of men by His word, ministers of the word are necessary to exercise this jurisdiction—men endowed with wisdom, understanding, and prudence. The word, says the apostle, is like a two-edged sword, or it is one that cuts on both sides, for it penetrates into the hearts and thoughts of man and into their very marrow (Hebrews 4:12). We also know what Paul says,

“When an unbeliever comes into your assembly, his conscience is searched, so that he will be constrained to fall down and to give glory to God” (1 Corinthians 14:24–25).

To the same purpose is this saying of Christ, “When the Spirit is come, He will judge the world,” (John 16:8).

For by the Spirit He means the preaching of the Gospel. It is then necessary that the ministers of the word, in order that they may faithfully and profitably perform their office, should be taught to understand the deceits and subterfuges by which men are accustomed to deceive. As, then, there are many hidden things in the hearts of men, he who would teach effectively must know that the innermost recesses of the heart must be probed and searched.

The Prophet had heard from God that the people over whom He was appointed were deceitful and filled with guile and fraud: You, He says, dwell in the midst of a deceitful people; as if He had said, “You have to deal with dishonest men, who not only openly betray their wickedness but also deceive when they pretend any repentance or profess obedience to God. So that they may not therefore weaken or cajole your resolution by their deceptions, settle it in your mind that you will have to contend with their wiles.” This is one reason.

There is another reason; for as God’s servants ought to know their wiles, which they are commanded to reprove, so there is need of courage and perseverance, lest hypocrisy should dishearten them. For such a thought as this may occur to the minds of God’s servants: “What shall I do? For the thoughts of men are hidden from me; now the truth ought to penetrate into the whole soul, but I do not know what lies hidden within anyone.” Thus pious teachers might be weakened in their efforts and disheartened, or wholly discouraged, unless God supported them. It was then for this reason that Jeremiah was expressly told that he had to deal with a deceitful and false people.

Afterward, He adds, Through guile they refuse to know Me. God had complained before that He was not known by the people, but He now exaggerates their crime by saying that they craftily evaded every light, as if He had said that they could not plead ignorance or any levity. For through guile, says God, they refuse to know Me. As they wholly flattered themselves with deceptions, they intentionally extinguished, as far as they could, the light. By guile then, He means that obstinate craftiness by which the people cast aside every instruction.