Matthew Poole and continuators on 2 Samuel 20:15

15 And they came and besieged him in Abel of Bethmaachah, and they cast up a bank against the city , and it stood in the trench : and all the people that were with Joab, † battered the wall to throw it down:

i. e. Ioab and his Army, which is easily understood, both from the foregoing and following Verses.

From whence they might either batter the Wall, or shoot at those who defended it against them, who should Assault it. See 2 King. 19. 32. Ier. 32. 24. and 33. 4. Otherwise, they threw down the bank of the City, which they had raised up to Defend the City on the weakest side.

i. e. The Bank stood in, or near to the Trench, or the Wall of the City; so that the City was in great danger of being taken. Otherwise, the City stood within the Trench, or Wall, being Defended onely by a single Trench, or a weak Wall; the Bank which was raised up there to Defend it, being thrown down.

Marginal references: Or, it stood against the outmost Wall.; ‡ Heb. marred to throw down.