The word "he" refers to God and is a metonym for his angels, as they are the ones who will gather the elect. Alternate translation: "they will gather" or "his angels will gather" (See: [[rc://en/ta/man/translate/figs-metonymy]])
The whole earth is spoken of as "the four winds," which refer to the four directions: north, south, east, and west. Alternate translation: "the north, south, east, and west" or "all parts of the earth" (See: [[rc://en/ta/man/translate/figs-metaphor]])
These two extremes are given to emphasize that the elect will be gathered from the entire earth. Alternate translation: "from every place on earth" (See: [[rc://en/ta/man/translate/figs-merism]])