John Gill Commentary 2 Kings 7:12

"And the king arose in the night, and said unto his servants, I will now show you what the Syrians have done to us. They know that we are hungry; therefore are they gone out of the camp to hide themselves in the field, saying, When they come out of the city, we shall take them alive, and get into the city." — 2 Kings 7:12 (ASV)

And the king arose in the night
Upon the report made to him:

and he said unto his servants, I will now show you what the Syrians
have done to us ;
taking it to be a stratagem of theirs to decoy them:

they know that we be hungry ;
and would be glad to come out of the city to get some food:

therefore are they gone out of the camp to hide themselves in the
field ;
to make us believe that they have broke up the siege, and have deserted the camp, and are gone, when they only lie in ambush:

saying, when they come out of the city ;
which they supposed they would do through hunger:

we shall catch them alive ;
take them captive at once:

and get into the city ;
being open to let them out, and receive them on their return.