The understood verb may be supplied. Alternate translation: "that neither they nor their ancestors have known" (See: [[rc://en/ta/man/translate/figs-ellipsis]])
Here the word "sword" refers to an enemy army. Alternate translation: "I will send an army of soldiers to fight against them" (See: [[rc://en/ta/man/translate/figs-metonymy]])
This is a metonym for Yahweh causing the people's enemies to destroy them. Alternate translation: "I have caused their enemies to completely destroy them" (See: [[rc://en/ta/man/translate/figs-metonymy]])