James 3:8

But nobody can tame the tongue. It is a restless evil, full of deadly poison.

Psalm 140:3

They have sharpened their tongues like a serpent. Viper's poison is under their lips. Selah.

Romans 3:13

"Their throat is an open tomb. With their tongues they have used deceit." "The poison of vipers is under their lips;"

Ecclesiastes 10:11

If the serpent bites before it is charmed, then is there no profit for the charmer's tongue.

Deuteronomy 32:33

Their wine is the poison of serpents, The cruel venom of asps.

Psalm 55:21

His mouth was smooth as butter, but his heart was war. His words were softer than oil, yet they were drawn swords.

Psalm 57:4

My soul is among lions. I lie among those who are set on fire, even the sons of men, whose teeth are spears and arrows, and their tongue a sharp sword.

Psalm 58:4

Their poison is like the poison of a serpent; like a deaf viper that stops its ear,

Psalm 59:7

Behold, they spew with their mouth. Swords are in their lips, "For," they say, "who hears us?"

Psalm 64:3-4

who sharpen their tongue like a sword, and aim their arrows, deadly words,

James 3:6

And the tongue is a fire. The world of iniquity among our members is the tongue, which defiles the whole body, and sets on fire the course of nature, and is set on fire by hell.

Revelation 12:9

The great dragon was thrown down, the ancient serpent, he who is called the devil and Satan, the deceiver of the whole world. He was thrown down to the earth, and his angels were thrown down with him.

Treasury of Scripture Knowledge

Summary

But the tongue can no man tame; it is an unruly evil, full of deadly poison.

General references

Bible References

An unruly

James 3:6
And the tongue is a fire. The world of iniquity among our members is the tongue, which defiles the whole body, and sets on fire the course of nature, and is set on fire by hell.
Psalm 55:21
His mouth was smooth as butter, but his heart was war. His words were softer than oil, yet they were drawn swords.
Psalm 57:4
My soul is among lions. I lie among those who are set on fire, even the sons of men, whose teeth are spears and arrows, and their tongue a sharp sword.
Psalm 59:7
Behold, they spew with their mouth. Swords are in their lips, "For," they say, "who hears us?"
Psalm 64:3
who sharpen their tongue like a sword, and aim their arrows, deadly words,

Full

Deuteronomy 32:33
Their wine is the poison of serpents, The cruel venom of asps.
Psalm 58:4
Their poison is like the poison of a serpent; like a deaf viper that stops its ear,
Psalm 140:3
They have sharpened their tongues like a serpent. Viper's poison is under their lips. Selah.
Ecclesiastes 10:11
If the serpent bites before it is charmed, then is there no profit for the charmer's tongue.
Romans 3:13
"Their throat is an open tomb. With their tongues they have used deceit." "The poison of vipers is under their lips;"
Revelation 12:9
The great dragon was thrown down, the ancient serpent, he who is called the devil and Satan, the deceiver of the whole world. He was thrown down to the earth, and his angels were thrown down with him.

General references

Matthew 15:18
But the things which proceed out of the mouth come out of the heart, and they defile the man.