Charles Ellicott Commentary Isaiah 62:8

"Jehovah hath sworn by his right hand, and by the arm of his strength, Surely I will no more give thy grain to be food for thine enemies; and foreigners shall not drink thy new wine, for which thou hast labored:" — Isaiah 62:8 (ASV)

The Lord has sworn ... —The principle of the Epistle to the Hebrews (Hebrews 6:13) is recognized here. Jehovah can swear by nothing less than that which is the symbol of His own greatness, identified with Himself.

I will no more give your corn ... —The words throw us back upon the early history of Israel, subject at any time to the desolating attacks of Midianites (Judges 6:4; Judges 6:11), Assyrians (Isaiah 16:9), and Philistines (2 Chronicles 28:18). The new blessing stands in special contrast with the curse of Deuteronomy 28:33; Deuteronomy 28:51.