2. There shall be a wonderful change wrought in them by that which is taught them, v. 4. (1.) They shall have a clear head, and be able to discern things that differ, and distinguish concerning them. The heart of those that were hasty and rash, and could not take time to digest and consider things, shall now be cured of their precipitation, and shall understand knowledge; for the Spirit of God will open their understanding. This blessed work Christ wrought in his disciples after his resurrection (Luke xxiv. 45), as a specimen of what he would do for all his people, in giving them an understanding, 1 John v. 20. The pious designs of good princes are likely to take effect when their subjects allow themselves liberty to consider, and to think, so freely as to take things right. (2.) They shall have a ready utterance: The tongue of the stammerers, that used to blunder whenever they spoke of the things of God, shall now be ready to speak plainly, as those that understand what they speak of, that believe, and therefore speak. There shall be a great increase of such clear, distinct, and methodical knowledge in the things of God, that those from whom one would not have expected it shall speak intelligently of these things, very much to the honour of God and the edification of others. Their hearts being full of this good matter, their tongues shall be as the pen of a ready writer, Ps. xlv. 1.