Proverbs 18:4 uses the same 'deep waters' metaphor for words, while Proverbs 20:5 applies it to the heart's purpose. Both explore hidden depths of human thought.

1 Samuel 20:12 shows Jonathan promising to discreetly uncover his father's feelings—a practical example of drawing out what is hidden, as Proverbs 20:5 describes.

Psalm 64:6 describes the inward mind and heart as 'deep,' mirroring Proverbs 20:5's 'deep water' imagery for hidden intentions. Both emphasize the depth of human inner thoughts.