‘For it is the day of Yahweh's vengeance,
The year of recompense in the controversy of Zion.'
Yahweh's day has finally come on Edom, the day when He revenges His people, and when sin too is dealt with. It is the day when Edom receive recompense for what they have done. This is one of many ‘days of Yahweh' from the beginning to the end of time, each one of which mirrors the final great day of Yahweh in the final judgment.
‘The year of recompense in the controversy of Zion.' This particularly applies the vengeance to their attitude towards God's people. The ‘controversy of Zion' may refer to their taking advantage of Judah's weak condition (2 Chronicles 28:17; Joel 3:19); the controversy over their rights to land which Edom have taken or had given to them by Assyria, which they are seen by Jerusalem as having no right to; and their general hostility towards Israel. Or to the original controversy when Edom refused passage to the children of Israel (Numbers 20:14-21). Or indeed to all the continued controversy between such neighbours. Or it may signify the continual controversy between the people of God and the world arising from their distinctive faith. With regard to Edom God is now settling the matter once and for all.