on Joel 2 :30
Wonders in the heavens and in the earth - This refers to those dreadful sights, dreadful portents, and destructive commotion, by which the Jewish polity was finally overthrown, and the Christian religion established in the Roman empire. See how our Lord applies this prophecy, Matthew 24:29 (note), and the parallel texts.
on Joel 2 :30
And I will shew wonders - Each revelation of God prepares the way for another, until that last revelation of His love and of His wrath in the Great Day. In delivering His people from Egypt, "the Lord shewed signs and wonders, great and sore, upon Egypt Deuteronomy 6:22. Here, in allusion to it, He says, in the same words, of the new revelation, "I will shew," or "give, wonders, or wondrous signs," (as the word includes both) wonders beyond the course and order of nature, and portending other dispensations of God, of joy to His faithful, terror to His enemies. As when Israel came out of Egypt, "the pillar of the cloud was a cloud and darkness to the camp of the Egyptians," but "gave light by night" to the "camp of Israel" Exodus 14:19-20, so all God's workings are light and darkness at once, according as people are, who see them or to whom they come. These wonders in heaven and earth "began in" the First Coming and "Passion of Christ, grew in the destruction of Jerusalem, but shall be perfectly fulfilled toward the end of the world, before the final Judgment, and the destruction of the Universe." At the birth of Christ, there was "the star" which appeared unto the wise men, "and the multitude of the heavenly host," whom the shepherds saw. At His Atoning Death, "the sun was darkened," there was the three hours' darkness over the whole land; and on earth "the veil of the temple was rent in twain from the top to the bottom, and the earth did quake, and the rocks rent, and the graves were opened" Luke 23:44-45; Matthew 27:45, Matthew 27:51-52 : and the Blood and water issued from the Saviour's side. After His Resurrection, there was the vision of Angels, terrible to the soldiers who watched the sepulchre, comforting to the women who sought to honor Jesus. His Resurrection was a sign on earth, His Ascension in earth and heaven. But our Lord speaks of signs both in earth and heaven, as well before the destruction of Jerusalem, as before His second Coming.
With regard to the details, it seems probable that this is an instance of what we may call an inverted parallelism, that having mentioned generally that God would give "signs in (1) heaven and (2) earth," the prophet first instances the "signs in earth," and then those "in heaven." A very intellectual Jewish expositor has suggested this, and certainly it is frequent enough to be, in conciser forms, one of the idioms of the sacred language. In such case, "the blood and fire and pillars of smoke, will be signs in earth; the turning of the sun into darkness and the moon into blood will be signs in heaven." When fortelling the destruction of Jerusalem, the Day of vengeance, which fell with such accumulated horror on the devoted city, and has for these 1800 years dispersed the people of Israel to the four winds, our Lord mentions first the signs on earth, then those in heaven. "Nation shall arise against nation, and kingdom against kingdom, and great earthquakes shall be in divers places, and famines, and pestilences; and fearful sights and great signs shall there be from heaven. Luke 21:10-11. Before the Day of Judgment our Lord also speaks of both Luke 21:25-26;
(1) "there shall be signs in the sun and in the moon and in the stars;
(2) and upon the earth distress of nations with perplexity; the sea and the waves roaring; people's hearts failing them for fear and for looking after those things which are coming on the earth, for the powers of heaven shall be shaken."
The Jewish historian relates signs both in heaven and in earth, before the destruction of Jerusalem. : "A star stood like a sword over Jerusalem;" "a light which, when the people were assembled at the Passover at 9 at night, shone so brightly around the altar and the temple, that it seemed like bright day, and this for half an hour; the eastern door of the temple, which 20 men scarcely shut at eventide, stayed with iron-bound bars and very deep bolts let down into the threshhold of one solid stone, was seen at 6 o'clock at night to open of its own accord; chariots and armed troops were seen along the whole country, coursing through the clouds, encircling the cities; at the feast of Pentecost, the priests entering the temple by night, as their wont was for worship, first perceived a great movement and sound, and then a multitudinous voice, 'Let us depart hence.'" These signs were authenticated by the multitude or character of those who witnessed them.
on Joel 2 :30
2:30 Wonders - They who read what historians report of these times, will see this fulfilled in the very letter. Blood - Possibly eruption of blood, as some fountains have been reported to have run with blood, prefiguring the great effusion of blood by the sword, and wars following. Fire - Either breaking out of the earth, or lightning in the air.