15. For—resumptive in connection with Ob 10, wherein Edom was threatened with cutting off for ever.
the day of the Lord—the day in which He will manifest Himself as the Righteous Punisher of the ungodly peoples (Joe 3:14). The "all" shows that the fulfilment is not exhausted in the punishment inflicted on the surrounding nations by the instrumentality of Nebuchadnezzar; but, as in Joe 3:14, and Zec 12:3, that the last judgment to come on the nations confederate against Jerusalem is referred to.
as thou hast done, it shall be done unto thee—the righteous principle of retribution in kind (Le 24:17; Mt 7:2; compare Jud 1:6, 7; 8:19; Es 7:10).
thy reward—the reward of thy deed (compare Isa 3:9-11).