Albert Barnes Commentary Jeremiah 46:10

"For that day is [a day] of the Lord, Jehovah of hosts, a day of vengeance, that he may avenge him of his adversaries: and the sword shall devour and be satiate, and shall drink its fill of their blood; for the Lord, Jehovah of hosts, hath a sacrifice in the north country by the river Euphrates." — Jeremiah 46:10 (ASV)

Rather, that day belongs to the Lord Yahweh of hosts. They march forth in haughty confidence, but that day, the day to which they are looking forward in proud hope of victory, is Yahweh’s day, a day on which they will be the victims sacrificed in His honor.