"and in the chambers, fright": If he saw the sword entering the marketplace, if he could flee from it, then the chambers of his heart would pound with fright, which would kill him.
Variantly: "On the outside the sword shall devour": because of what they did in the thoroughfares (i.e., idolatry), viz. (Jeremiah 11:13) "For (as) the number of your cities was (the number of) your gods, O Judah, and (as) the number of streets in Jerusalem have you made altars to the shame — altars to sacrifice to the ba'al." "and in the chambers, fright": what they do in their secret chambers, viz. (Ezekiel 8:12) "what the elders of the house of Israel do in the darkness … For they say: 'The L-rd does not see us; the L-rd has left the land."