In the lips of him that hath understanding wisdom is found: but a rod is for the back of him that is void of understanding.
– Proverbs 10:13
[T]he word for understanding means to separate mentally. We would refer to that as discernment—thinking through something and being able to make distinctions and determine whether good or bad. We might also think of it as insight. The one who has an understanding mind, or heart, will speak forth wisdom (Proverbs 10:11, 21; 15:7). Jesus also taught in the Gospels that the source of our speech is our heart, or mind (Luke 6:45). The man void of understanding does not discern and goes on in the way of folly. Because he will not receive instruction, he will come to the rod of correction (Proverbs 7:22; 26:3; Psalm 32:8-9).