Theophylact of Ohrid

Observe that Christ sends the Angels as well as the Father; where then are they who say that He is not equal to the Father? For the Angels go forth to gather together the faithful, who are chosen, that they may be carried into the air to meet Jesus Christ. Wherefore it goes on: And gather together his elect from the four winds.

Catena Aurea by Aquinas ↗

Augustine of Hippo

That he will gather his elect from the four winds means from the whole world. For Adam himself, as I have shown, signifies in Greek the whole world, with the four letters (A, D, A, M). As the Greeks think of these matters, the four quarters of the world have these initial letters, Anatole (east), Dysis (west), Arktos (north), and Mesembria (south). Adam after the fall has been scattered over the whole world. He was in one place, but fell, and as if crushed in tiny pieces, his progeny filled the whole world. …

On The Psalms 96.13 ↗

Bede

And then he will send his angels, and they will gather his elect from the four winds, from the ends of the earth to the ends of the sky. By the four winds, he means the four quarters of the world: East, West, North, and South. And lest anyone think it was only from the four sides of the earth, and not rather from its entire bounds including the interior regions, he aptly added: From the ends of the earth to the ends of the sky, that is, from the extreme borders of the earth straight to its farthest limits, where, to those gazing …

On the Gospel of Mark ↗