And the heart of fools shall understand knowledge, and the tongue of stammerers shall speak readily and plain.

And the heart of those hastened Understandeth to know, And the tongue of stammerers hasteth to speak clearly.

The man of sudden impulses will become wise in heart, and he whose tongue is slow will get the power of talking clearly.

And the heart of the foolish will understand knowledge, and the tongue of those with impaired speech will speak quickly and plainly.

Et cor stultorum intentum erit ad scientiam, et lingua balborum expedita erit ad loquendum diserte.

The heart also of the rash - Margin, 'Hasty.' The Hebrew word denotes those who hasten; that is, those who are precipitate in forming a judgment, or deciding on a course of action. They do not take time to deliberate, and consequently they are led headlong into error, and into improper courses of life.
Shall understand knowledge - They shall take time to deliberate; and they shall consequently form a more enlightened judgment.
And the tongue of the stammerers - The 'stammerers' (compare the note at Isaiah 28:11) seem here to denote those who had indistinct and confused views of subjects, or who were incapable of expressing clear and intelligible views of divine truth.
Shall be ready to speak plainly - Margin, 'Elegantly.' The Hebrew is צתות tsâthôth 'clear,' 'white,' usually applied to a bright, clear, white light. The sense is, that there should be no indistinctness or obscurity in their views and modes of utterance.

The heart also of the rash shall understand knowledge,.... Such who have been hasty and precipitant, as the word (c) signifies; who have not given themselves time to consider what they have read or heard, or has been proposed unto them, and have hastily received every thing that has been suggested to them, especially by carnal sense and reason, shall now sit down, and coolly consider things, and so gain an understanding of divine and spiritual knowledge, of the knowledge of Christ, of his person, offices, grace, righteousness, and salvation; an experimental knowledge and understanding of these things, heart and not head knowledge:
and the tongue of the stammerer shall be ready to speak plainly; or, "shall make haste to speak neatly" (d); elegantly and politely; such who hesitated in their speech, and spoke in a blundering manner, and scarcely intelligibly, especially when they spoke of divine and spiritual things, yet now, without the least hesitation, in the freest and most ready manner, with all plainness and propriety shall talk of these things, to the great delight, satisfaction, and use of those that hear them: this was true of the apostles of Christ, those babes and sucklings, out of whose mouth God ordained praise, and who were most of them Galilaeans, very illiterate and unpolished, and yet these, especially when they had the gift of tongues, spake the great things of God very readily, and in good language; and also is true of other ministers of the word, raised up among the barbarous nations of the world.
(c) "inconsideratorum", Junius & Tremellius, Piscator; "praecipatorum", Montanus. (d) "festinabit loqui nitida", Pagninus; "polite", Munster; "diserte", Calvin; "loqui venusta", Cocceius.

rash--rather, "the hasty"; contrast "shall not make haste" (Isaiah 28:16); the reckless who will not take time to weigh religious truth aright. Or else, the well-instructed [HORSLEY].
stammers--those who speak confusedly on divine things (compare Exodus 4:10-12; Jeremiah 1:6; Matthew 10:19-20). Or, rather, those drunken scorners who in stammering style imitated Isaiah's warnings to mock them [MAURER] (Isaiah 28:7-11, Isaiah 28:13-14, Isaiah 28:22; Isaiah 29:20); in this view, translate, "speak uprightly" (agreeably to the divine law); not as English Version, referring to the distinctness of articulation, "plainly."

The rash - Who were hasty in judging of things; which is an argument of ignorance and folly. The tongue - That used to speak of the things of God, darkly, and doubtfully; which though it was in part fulfilled in Hezekiah, yet was truly and fully accomplished only by Christ, who wrought this wonderful change in an innumerable company both of Jews and Gentiles.