Matthew Poole and continuators on Proverbs 15:7

7 The Lips of the wise disperse knowledge , but the heart of the foolish doth not so .

Freely communicate to others what they know, as they have opportunity.

Either because he hath no knowledg to disperse, or because he hath not an heart to perform his duty, or to do good to others. Or, as others render it, and as the last Hebrew word is rendred, Gen. 42. 34. and elsewhere, is not right; or, the place may be rendred, the heart of foolish (understand out of the former clause, as is very usual, disperseth by his Lips) that which is not right, foolish and corrupt discourse, which is fitly opposed to knowledg.