Charles Ellicott Commentary Isaiah 37:33

"Therefore thus saith Jehovah concerning the king of Assyria, He shall not come unto this city, nor shoot an arrow there, neither shall he come before it with shield, nor cast up a mound against it." — Isaiah 37:33 (ASV)

Nor come before it with shields. —The clause points to the two forms of attack:

1. the invaders marching to the assault, protected by their serried shields against the darts and stones which were flung by hand or from engines by the besieged; and
2. the earthworks which were piled up to make the attack on the walls more feasible.

(Ezekiel 4:2.) Isaiah’s prediction is not only that Jerusalem will not be taken, but that the enemy, though now encamped around it, will not even proceed to the usual operations of a siege.