Jeremiah 9:5
"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."
Cross References (ranked by relevance)
Behold, is it not of the LORD of hosts that the people shall labour in the very fire, and the people shall weary themselves for very vanity?
For the rich men thereof are full of violence, and the inhabitants thereof have spoken lies, and their tongue is deceitful in their mouth.
For thy mouth uttereth thine iniquity, and thou choosest the tongue of the crafty.
Thou art wearied in the greatness of thy way; yet saidst thou not, There is no hope: thou hast found the life of thine hand; therefore thou wast not grieved.
Speaking lies in hypocrisy; having their conscience seared with a hot iron;
And they bend their tongues like their bow for lies: but they are not valiant for the truth upon the earth; for they proceed from evil to evil, and they know not me, saith the LORD.
Their tongue is as an arrow shot out; it speaketh deceit: one speaketh peaceably to his neighbour with his mouth, but in heart he layeth his wait.
Should thy lies make men hold their peace? and when thou mockest, shall no man make thee ashamed?
They have sharpened their tongues like a serpent; adders’ poison is under their lips. Selah.
Wherefore putting away lying, speak every man truth with his neighbour: for we are members one of another.
Behold, he travaileth with iniquity, and hath conceived mischief, and brought forth falsehood.
O my people, what have I done unto thee? and wherein have I wearied thee? testify against me.
For they sleep not, except they have done mischief; and their sleep is taken away, unless they cause some to fall.
Woe unto them that draw iniquity with cords of vanity, and sin as it were with a cart rope:
She hath wearied herself with lies, and her great scum went not forth out of her: her scum shall be in the fire.
Who whet their tongue like a sword, and bend their bows to shoot their arrows, even bitter words:
Thou givest thy mouth to evil, and thy tongue frameth deceit.
And they smote the men that were at the door of the house with blindness, both small and great: so that they wearied themselves to find the door.