“his eye will be evil.” The “evil eye” is a Semitic idiom for being greedy and stingy. Deuteronomy 28 is revealing how the people of Israel will be cursed if they do not keep God’s Law. There will be such shortages that even the man who is tender among the Israelites will have an evil eye towards his family, that is, be stingy and selfish when it comes to even them. Biblically, an evil eye is greedy or stingy; while a “good eye,” or a “single eye,” is generous. This verse shows us that terrible times can cause people to turn against their families, and in the siege, the man will be stingy and will withhold good from his family and keep it for himself, which is the fallen human nature at its worst.
[For more on idioms involving the good eye, see commentary on Prov. 22:9. For more on the idiom of the evil eye, see commentary on Prov. 28:22.]