Moreover - These verses Isaiah 29:5, Isaiah 29:7-8 contain a beautiful description of the destruction of the army of Sennacherib. Though they had laid the plan of a regular siege; though the city, in itself, would not be able to hold out against them, and all was alarm and conscious imbecility within; yet in an instant the siege would be raised, and the advancing hosts of the Assyrians would all be gone.
The multitude of thy strangers - The multitude of the strangers that shall besiege thee; called ‘thy strangers,’ because they besieged, or oppressed thee. The word ‘strangers’ here, as elsewhere, means “foreigners” (see the note at Isaiah 1:7; compare Isaiah 2:6; Isaiah 5:17; Isaiah 14:1; Isaiah 25:2, Isaiah 25:5; Isaiah 29:5; Isaiah 60:10).
Shall be like small dust - Light, fine dust that is easily dissipated by the wind.
Of the terrible ones - Of the invading, besieging army, that is so much the object of dread.
As chaff that passeth away - (see the note at Isaiah 17:13). This image of chaff driven before the wind, to denote the sudden and entire discomfiture of enemies, is common in the Scriptures (see Job 21:18; Psalms 1:4; Psalms 35:5; Hosea 13:13).
Yea, it shall be at an instant suddenly - The forces of Sennacherib were destroyed in a single night by the angel of the Lord (Isaiah 37:36; the note at Isaiah 10:12, Isaiah 10:28-34, note), and the siege of Jerusalem was of course immediately raised.