Albert Barnes Commentary Proverbs 20:5

"Counsel in the heart of man is [like] deep water; But a man of understanding will draw it out." — Proverbs 20:5 (ASV)

The contest between reticence on one side and pertinacity in search on the other is represented as by a parable. The well may be very deep (compare the marginal reference), but the man of understanding has enough skill to draw up the water even to the last drop. Every question is, as it were, a turning of the windlass.