Jamieson, Fausset and Brown on Isaiah 29:2

2. Yet--rather, "Then."

heaviness ... sorrow--rather, preserving the Hebrew paronomasia, "groaning" and "moaning."

as Ariel--either, "the city shall be as a lion of God," that is, it shall emerge from its dangers unvanquished; or "it shall be as the altar of burnt offering," consuming with fire the besiegers (Is 29:6; Is 30:30; 31:9; Le 10:2); or best, as Is 29:3 continues the threat, and the promise of deliverance does not come till Is 29:4, "it shall be like a hearth of burning," that is, a scene of devastation by fire [G. V. Smith]. The prophecy, probably, contemplates ultimately, besides the affliction and deliverance in Sennacherib's time, the destruction of Jerusalem by Rome, the dispersion of the Jews, their restoration, the destruction of the enemies that besiege the city (Zec 14:2), and the final glory of Israel (Is 29:17-24).