William Burkitt on Matthew 12:36

I say unto you; I, that have always been in my Father's bosom, and fully know his mind; I, that am constituted Judge of quick and dead, and understand the rule of judgment; I, even I, do assure you that every word that has no tendency to promote the glory of God, or some way the good of others, will fall under censure at the great day, without an intervening repentance.

Note here, That there are two sorts of words for which we must be judged; sinful words, and idle words.

Sinful words are blasphemous words, censorious words, lying and slandering words.

Idle words are such as savour nothing of wisdom and piety; that have no tendency to make men either wiser or better: how light soever men make of their words now, yet in God's balance another day they will be found to weigh very heavy.

What a bridle should this text be to extravagant tongues! Let your speech be always seasoned with salt Col 4:6, that is, with wisdom, &c., for our words may mischief others a long time after they are spoken.

How many years may a frothy or a filthy word, a profane scoff, an atheistical jest, stick in the minds of them that hear it, after the tongue that spake it is dead!

A word spoken is physically transient, but morally permanent.