Adam Clarke's Commentary on the Bible

Verse 13 (Proverbs 12:13)

The wicked is snared by the transgression of his lips - A man who deals in lies and false oaths will sooner or later be found out to his own ruin. There is another proverb as true as this: A liar had need of a good memory; for as the truth is not in him, he says and unsays, and often contradicts himself.

- Adam Clarke's Commentary on the Bible