3. go out at the breaches--namely, of the city walls broken by the enemy.
      every cow at that which is before her--figurative for the once luxurious nobles (compare "kine of Bashan," Am 4:1) shall go out each one right before her; not through the gates, but each at the breach before him, not turning to the right or left, apart from one another.
      ye shall cast them into the palace--"them," that is, "your posterity," from Am 4:2. You yourselves shall escape through the breaches, after having cast your little children into the palace, so as not to see their destruction, and to escape the more quickly. Rather, "ye shall cast yourselves into the palace," so as to escape from it out of the city [CALVIN]. The palace, the scene of the princes' riots (Am 3:10, 15; 4:1), is to be the scene of their ignominious flight. Compare in the similar case of Jerusalem's capture, the king's escape by way of the palace, through a breach in the wall (Eze 12:5, 12). GESENIUS translates, "Ye shall be cast (as captives) into the (enemy's) stronghold"; in this view, the enemy's stronghold is called "palace," in retributive contrast to the "palaces" of Israel's nobles, the store houses of their robberies (Am 3:10).

JFB.