Jamieson, Fausset and Brown on Isaiah 26:18

18. brought forth wind--Michaelis explains this of the disease empneumatosis. Rather, "wind" is a figure for that which proves an abortive effort. The "we" is in antithesis to "Thy," "my" (Is 26:19), what we vainly attempt, God will accomplish.

not wrought ... deliverance in ... earth--literally, "the land (Judea) is not made security," that is, is not become a place of security from our enemies.

neither ... world fallen--The "world" at large, is in antithesis to "the earth," that is, Judea. The world at enmity with the city of God has not been subdued. But Maurer explains "fallen," according to Arabic idiom, of the birth of a child, which is said to fall when being born; "inhabitants of the world (Israel, Is 24:4; not the world in general) are not yet born"; that is, the country as yet lies desolate, and is not yet populated.