"You shall not bear false witness against your neighbor.”
Exodus 20:16

We’ll end our considerations on the ninth commandment with thoughts regarding how much God hates lying (and other sins of the tongue).

These six things the LORD hates, Yes, seven are an abomination to Him: A proud look, A lying tongue, Hands that shed innocent blood, A heart that devises wicked plans, Feet that are swift in running to evil, A false witness who speaks lies, And one who sows discord among brethren.
Proverbs 6:16-19

Of the seven things God says are an abomination to Him, note that number two and number six are about how He hates lying. Not also that number seven is nearly always the result of sinful talking.

Note also the severe damage even a few words unfitly spoken frequently cause.

For we all stumble in many things. If anyone does not stumble in word, he is a perfect man, able also to bridle the whole body. Indeed, we put bits in horses' mouths that they may obey us, and we turn their whole body. Look also at ships: although they are so large and are driven by fierce winds, they are turned by a very small rudder wherever the pilot desires. Even so the tongue is a little member and boasts great things. See how great a forest a little fire kindles! And the tongue is a fire, a world of iniquity. The tongue is so set among our members that it defiles the whole body, and sets on fire the course of nature; and it is set on fire by hell. For every kind of beast and bird, of reptile and creature of the sea, is tamed and has been tamed by mankind. But no man can tame the tongue. It is an unruly evil, full of deadly poison. With it we bless our God and Father, and with it we curse men, who have been made in the similitude of God.
James 3:2-9

How then shall we speak?

Therefore, putting away lying, "Let each one of you speak truth with his neighbor," for we are members of one another. "Be angry and sin do not sin'“: do not let the sun go down on your wrath, nor give place to the devil… Let no corrupt word proceed out of your mouth, but what is good for necessary edification, that it may impart grace to the hearers... Let all bitterness, wrath, anger, clamor, and evil speaking be put away from you, with all malice. And be kind to one another, tenderhearted, forgiving one another, even as God in Christ forgave you.
Ephesians 4:25-6, 29, 31-32