Jeremiah 9:5

5 Friend deceives friend, and no one speaks the truth. They have taught their tongues to lie; they weary themselves with sinning.

Read Jeremiah 9:5 Using Other Translations

And they will deceive every one his neighbour, and will not speak the truth: they have taught their tongue to speak lies, and weary themselves to commit iniquity.
Everyone deceives his neighbor, and no one speaks the truth; they have taught their tongue to speak lies; they weary themselves committing iniquity.
They all fool and defraud each other; no one tells the truth. With practiced tongues they tell lies; they wear themselves out with all their sinning.

What does Jeremiah 9:5 mean?

John Gill's Exposition of the Bible
Jeremiah 9:5

And they will deceive everyone his neighbour
In conversation, with lying words; and in trade and commerce, by art and tricking: and will not speak the truth;
with respect to facts they report, or goods they sell: they have taught their tongue to speak lies;
and become so accustomed to lying that they cannot do otherwise; it is as it were natural to them: and weary themselves to commit iniquity;
spared no pains to come at it, nor any in it, and go on even to weariness; are more laborious and indefatigable in committing sin than good men are in doing good; which shows great folly and stupidity. The Targum is,

``they are become foolish, they have erred.''
California - Do Not Sell My Personal Information  California - CCPA Notice