Jeremiah 9:4

"For every brother will utterly supplant, and every friend will walk deceitfully. And a man shall mock his brother, and they will not speak the truth, for they have bent their tongue like a bow for lies and not for truth." But often a pretended patience excites to anger more keenly than words, and a spiteful silence exceeds the most awful insults in words. The wounds of enemies are more easily borne than the deceitful blandishment of mockers, as is well said by the prophet.

(Verse 4 and following) Let each person guard themselves from their neighbor, and let them not have trust in any brother, for every brother will deceive and every friend will act deceitfully; and a man will mock his brother, and they will not speak the truth. For they have taught their tongue to speak lies (or their tongue has learned to speak lies), in order to act wickedly, they have labored (or acted unjustly) and have not ceased from turning away. Your dwelling is in the midst of deceit, in deceit (or usury upon usury, and deceit upon deceit); they refused (or did not want) to know me, says the Lord. This place should be used in times of persecution and distress, when either faith is rare or non-existent: when neither brother nor neighbor can be trusted, and the enemies of a man are those of his own household (Mich. 7): when, according to the Gospel, the father will betray the son, and the son the father, and two will be divided into three, and three into two. And what it implies, They have taught their tongue to speak falsehood, or their tongue has learned to speak falsehood (Matt. X), shows that the habit of lying is somehow turned into nature: and they diligently act so that they may do wicked things. And what follows, Your dwelling is in the midst of deceit, in deceit, is specifically directed to the Prophet, that he dwells among a lying people; or as the Seventy translated: Usury upon usury, and deceit upon deceit: and that they increase their crimes daily, and have no remorse for their previous actions, but rather accumulate past offenses with new ones. They do these things, with all zeal, so that they may not know the Lord, who did not command these things to be done.