Charles Ellicott Commentary 2 Kings 7:5

"And they rose up in the twilight, to go unto the camp of the Syrians; and when they were come to the outermost part of the camp of the Syrians, behold, there was no man there." — 2 Kings 7:5 (ASV)

In the twilight — that is, at nightfall. (See 2 Kings 7:9; 2 Kings 7:12). They waited until then, that their departure might not be noticed from the walls.

The uttermost part — that is, the outskirts or verge of the camp nearest to Samaria.