John Gill Commentary Joel 2:24

"And the floors shall be full of wheat, and the vats shall overflow with new wine and oil." — Joel 2:24 (ASV)

And the floors shall be full of wheat
The churches of Christ, which will now be in Judea, and in the Gentile world, which are his "floors", (Matthew 3:12); and which will be set up everywhere through the preaching of the Gospel, the descent of the former and latter rain; these will be full of precious souls gathered in, compared to wheat, and of the choice and excellent, doctrines of the Gospel, and of all spiritual provisions, (Matthew 13:30) (Jeremiah 23:28).

and the fats shall overflow with wine and oil;
with the wine of Gospel doctrine, and the oil of true grace; there shall be a flow, an overflow, a redundancy of these, both in the ministers of the word and private Christians, in whom the grace of God shall abound and superabound; see (Romans 5:20) (1 Timothy 1:14).