The general sense is plain. A man must for good or evil take the consequence of his words, as well as his deeds. Compare the marginal reference.

With the fruit of his mouth - Our own words frequently shape our good or evil fortune in life.

A man's belly shall be satisfied with the fruit of his mouth,.... With his own words and discourses, when they are prudent, pious, and savoury; when they are with grace, and minister it; they are satisfying to himself, to his own mind and conscience, and to his family; to all within his house, which is, as it were, his belly; but, if otherwise, it will not be profitable nor satisfying to either; and therefore, if a man would keep conscience easy, and be useful to others, he ought to take care what he says; see Proverbs 12:14;

and with the increase of his lips shall he be filled; the same thing as before, expressed in different words, alluding to the sowing, of seed in the earth, and the increase of it; as a man sows he reaps, and enjoys the fruits of his labour; according to what a man sows with his lips, such is his harvest he is afterwards a partaker of.

With Proverbs 18:19, the series of proverbs which began with that of the flatterer closes. The catchword אח, which occurred at its commencement, 9b, is repeated at its close, and serves also as a landmark of the group following Proverbs 18:20-24. The proverb of the breach of friendship and of contentions is followed by one of the reaction of the use of the tongue on the man himself.

Proverbs 18:20

20 Of the fruit which a man's mouth bringeth is his heart satisfied;

     By the revenue of his lips is he filled.

He will taste in rich measure of the consequences not merely of the good (Proverbs 12:14, cf. Proverbs 13:2), but of whatever he has spoken. This is an oxymoron like Matthew 15:11, that not that which goeth into the mouth, but that which cometh out of it, defileth a man. As at John 4:34 the conduct of a man, so here his words are called his βρῶμα. Not merely the conduct (Proverbs 1:31; Isaiah 3:10), but also the words are fruit-bringing; and not only do others taste of the fruit of the words as of the actions of a man, whether they be good or bad, but above all he himself does so, both in this life and in that which is to come.

A man's belly shall be satisfied with the fruit of his mouth; and with the increase of his lips shall he be filled.

18:20 Satisfied - Wise discourses tend to the satisfaction of the speaker, as well as to the good of the hearers.

20. (Compare Pr 12:14; 13:2). Men's words are the fruit, or, increase of his lips, and when good, benefit them.

satisfied with-(Compare Pr 1:31; 14:14).

18:19. Great care must be taken to prevent quarrels among relations and those under obligations to each other. Wisdom and grace make it easy to forgive; but corruption makes it difficult. 20. The belly is here put for the heart, as elsewhere; and what that is filled with, our satisfaction will be accordingly, and our inward peace. 21. Many a one has caused his own death, or the death of others, by a false or injurious tongue. 22. A good wife is a great blessing to a man, and it is a token of Divine favour. 23. Poverty tells men they must not order or demand. And at the throne of God's grace we are all poor, and must use entreaties. 24. Christ Jesus never will forsake those who trust in and love him. May we be such friends to others, for our Master's sake. Having loved his own, which were in the world, he loved them unto the end; and we are his friends if we do whatever he commands us, Joh 15:14.