Here’s a good context.
***Matthew 12: *** ***[33] Either make the tree good and its fruit good: or make the tree evil, and its fruit evil. For by the fruit the tree is known. [34] O generation of vipers, how can you speak good things, whereas you are evil? for out of the abundance of the heart the mouth speaketh. [35] A good man out of a good treasure bringeth forth good things: and an evil man out of an evil treasure bringeth forth evil things. [36] But I say unto you, that every idle word that men shall speak, they shall render an account for it in the day of judgment. [37] For by thy words thou shalt be justified, and by thy words thou shalt be condemned.
***Every idle word is pretty specific and unambiguous.
As for other suggestions…
***Galatians 5:13
For you, brethren, have been called unto liberty: only make not liberty an occasion to the flesh, but by charity of the spirit serve one another.
***1 Corinthians 8:9
But take heed lest perhaps this your liberty become a stumblingblock to the weak.
James 2:12
So speak ye, and so do, as being to be judged by the law of liberty.
1 Peter 2:16
As free, and not as making liberty a cloak for malice, but as the servants of God.
2 Peter 2:19
Promising them liberty, whereas they themselves are the slaves of corruption. For by whom a man is overcome, of the same also he is the slave.