Jerome : (Verse 5) And the Lord will create (or created) over every place of Mount Zion, and where he is invoked, a cloud by day, and smoke and the brightness of a flaming fire at night. For in Christ there is a new creation, of which we read elsewhere: The old things have passed away: behold, all things have become new (2 Corinthians 5:17). Regarding this, the Septuagint translated: And he will come, and there will be every place of Mount Zion, and all the things that are around it, a cloud will cover during the day, and the light of a flaming fire at night. But who will come except him, of whom it is written: He will come from Zion to free them (Isaiah 59:20, according to the Septuagint). And of whom another prophet mentions: Yet a little while, and he who is to come will come, and will not delay (Habakkuk 2:3). When he comes, the people will be restored to their former happiness, which they once had in the desert; the Lord will lead them during the day with a pillar of cloud, and during the night with a pillar of fire (Exodus 13): so that they may not be disturbed either in prosperity or in adversity. And in the psalm it is said: By day the sun shall not scorch you, nor the moon by night (Ps. CXX, 6). But in this place smoke signifies not error and ignorance, but glory, according to what we shall read in the same prophet, according to the opinion of some: And the house was filled with smoke (Isaiah 6). And in Joel, concerning the grace of the Holy Spirit which descends upon the apostles, it is said: I will pour out my spirit, and they shall prophesy (Joel II). And I will show wonders in the sky above and signs on the earth below, blood and fire and clouds of smoke (Acts 2:17). I think this signifies that which is said in the Psalms: He touches the mountains, and they smoke (Psalms 104:32). — Commentary on Isaiah