I. How the kingdom of grace shall be introduced by a plentiful effusion of the Spirit, (v. 28, 29). We are not at a loss about the meaning of this promise, nor in doubt what it refers to and wherein it had its accomplishment, for the apostle Peter has given us an infallible explication and application of it, assuring us that when the Spirit was poured out upon the apostles, on the day of Pentecost (Acts ii. 1, &c.), that was the very thing which was spoken of here by the prophet Joel, v. 16, 17. That was the gift of the Spirit, which, according to this prediction, was to come, and we are not to look for any other, any more than for another accomplishment of the promise of the Messiah. Now, 1. The blessing itself here promised is the pouring out of the Spirit of God, his gifts, graces, and comforts, which the blessed Spirit is the author of. We often read in the Old Testament of the Spirit of the Lord coming by drops, as it were, upon the judges and prophets whom God raised up for extraordinary services; but now the Spirit shall be poured out plentifully in a full stream, as was promised with an eye to gospel-times, Isa. xliv. 3. I will pour my Spirit upon thy seed. 2. The time fixed for this is afterwards; after the fulfilling of the foregoing promises this shall be fulfilled. St. Peter expounds this of the last days, the days of the Messiah, by whom the world was to have its last revelation of the divine will and grace in the last days of the Jewish church, a little before its dissolution. 3. The extent of this blessing, in respect of the persons on whom it shall be bestowed. The Spirit shall be poured out upon all flesh, not as hitherto upon Jews only, but upon Gentiles also; for in Christ there is no distinction between Jew and Greek, Rom. x. 11, 12. Hitherto divine revelation was confined to the seed of Abraham, none but those of the land of Israel had the Spirit of prophecy; but, in the last days, all flesh shall see the glory of God (Isa. xl. 5) and shall come to worship before him, Isa. lxvi. 23. The Jews understand it of all flesh in the land of Israel, and Peter himself did not fully understand it as speaking of the Gentiles till he saw it accomplished in the descent of the Holy Ghost upon Cornelius and his friends, who were Gentiles (Acts x. 44, 45), which was but a continuation of the same gift which was bestowed on the day of Pentecost. The Spirit shall be poured out upon all flesh, that is, upon all those whose hearts are made hearts of flesh, soft and tender, and so prepared to receive the impressions and influences of the Holy Ghost. Upon all flesh, that is, upon some of all sorts of men; the gifts of the Spirit shall not be so sparing, or so much confined, as they have been, but shall be more general and diffusive of themselves. (1.) The Spirit shall be poured out upon some of each sex. Not your sons only, but your daughters, shall prophesy; we read of four sisters in one family that were prophetesses, Acts xxi. 9. Not the parents only, but the children, shall be filled with the Spirit, which intimates the continuance of this gift for some ages successively in the church. (2.) Upon some of each age: "Your old men, who are past their vigour and whose spirits begin to decay, your young men, who have yet but little acquaintance with and experience of divine things, shall yet dream dreams and see visions;" God will reveal himself by dreams and visions both to the young and old. (3.) Upon those of the meanest rank and condition, even upon the servants and the handmaids. The Jewish doctors say, Prophecy does not reside on any but such as are wise, valiant, and rich, not upon the soul of a poor man, or a man in sorrow. But in Christ Jesus there is neither bond nor free, Gal. iii. 28. There were many that were called being servants (1 Cor. vii. 21), but that was no obstruction to their receiving the Holy Ghost. (4.) The effect of this blessing: They shall prophesy; they shall receive new discoveries of divine things, and that not for their own use only, but for the benefit of the church. They shall interpret scripture, and speak of things secret, distant, and future, which by the utmost sagacities of reason, and their natural powers, they could not have any insight into nor foresight of. By these extraordinary gifts the Christian church was first founded and set up, and the scriptures were written, and the ministry settled, by which, with the ordinary operations and influences of the Spirit, it was to be afterwards maintained and kept up.