And it shall come to pass afterward, that I will pour out my spirit upon all flesh; and your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions:
Afterward - "in the last days" (Isaiah 2:2) under Messiah, after the punishment of the Jews by the Gentile nations, and then after the invasion and deliverance of Israel from the northern army. Having heretofore stated the outward blessings, he now raises their minds to the expectation of extraordinary spiritual blessings, which constitute the true restoration of God's people (Isaiah 44:3). Fulfilled in the earnest of the Spirit given on Pentecost (Acts 2:16-17, "This (the outpouring of the Spirit on the assembled disciples) is that which was spoken by the prophet Joel; And it shall come to pass in the last days, saith God, I will pour out my Spirit upon all flesh," etc.), in the case of the elect remnant among the Jews, and the subsequent election of a people among the Gentiles; hereafter about to be realized more fully at the restoration of Israel (Isaiah 54:13; Jeremiah 31:9; Jeremiah 31:33-34; Ezekiel 39:29; Zechariah 12:10), and the consequent conversion of the whole world (Isaiah 2:2; Isaiah 11:9; Isaiah 66:18-23; Micah 5:7; Romans 11:12; Romans 11:15).
As the Jews have been the seedsmen of the elect Church gathered out of Jews and Gentiles, the first Gospel-preachers being Jews from Jerusalem, so they shall be the harvestmen of the coming world-wide Church, to be set up at Messiah's appearing. That the promise is not restricted to the first Pentecost appears from Peter's own words: "The promise is (not only) unto you, and to your children, (but also) to all that are afar off (both in space and in time), even as many as the Lord our God shall call" (Acts 2:39). So here, not merely upon the elect remnant and the Church now being gathered out of the world, but "upon all flesh." I will pour out-under the new covenant: not merely, let fall drops, as under the Old Testament (John 7:38-39).
My Spirit - the Spirit "proceeding from the Father and the Son," and at the same time One with the Father and the Son (cf. Isaiah 11:2).
Your sons and your daughters shall prophesy, your old men shall dream dreams, your young men shall see visions - not merely on a privileged few (Numbers 11:29), as the prophets of the Old Testament, but men of all ages and ranks. See Acts 21:9; and 1 Corinthians 11:5, "Every woman that prayeth or prophesieth." as to "daughters" -
i.e., women prophesying.
Dreams ... visions - (Acts 9:10, Ananias' vision concerning Saul; Acts 16:9, Paul's vision of the man of Macedonia). The "dreams" are attributed to the "old men" as more in accordance with their years; "visions" to the "young men," as adapted to their more energetic and lively minds. The three modes whereby God revealed His will under the Old Testament (Numbers 12:6), "prophecy, dreams, and visions," and "mouth to mouth" are here made the symbol of the full manifestation of Himself to all His people not only in miraculous gifts to some, but by His indwelling Spirit to all in the New Testament (John 14:21; John 14:23; John 15:15). In Acts 16:9, and also in the appearance of the Lord to Paul at Corinth, Acts 18:9, the term used is "vision," though in the night, not a dream. No other dream is mentioned in the New Testament except those given to Joseph in the very beginning of the New Testament, before the full Gospel come; and to the wife of Pilate, a Gentile (Matthew 1:20; Matthew 2:13; Matthew 27:19). "Prophesying" in the New Testament is applied to all speaking under the enlightenment of the Holy Spirit, and not merely to foretelling events. All true Christians are "priests" and "ministers" of our God (Isaiah 61:6, "Ye (Israelites of Zion, Joel 2:3) shall be named the Priests of the Lord: men shall call you the Ministers of our God: ye shall eat the riches of the Gentiles"), and have the Spirit (Ezekiel 36:26-27). Besides this, probably, a special gift of prophecy and miracle-working is to be given at or before Messiah's coming again.