The abstract noun "refuge," which means a shelter or a place safe from danger, can be stated as a verb. Alternate translation: "The eternal God will protect his people" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])
The words "everlasting arms" are a metaphor for Yahweh's promise to protect his people forever. Alternate translation: "he will support and take care of his people forever" (See: [[rc://en/ta/man/translate/figs-metaphor]])
Moses speaks of the future as if it were the past to emphasize that what he is saying will come true. Alternate translation: "He will thrust out ... he will say" (See: [[rc://en/ta/man/translate/figs-pastforfuture]])
Moses speaks to the Israelites as if they were one man, so the word "you" and the command "destroy" here are singular. (See: [[rc://en/ta/man/translate/figs-you]])
If this direct quotation would not work well in your language, you may change it to an indirect quotation. Alternate translation: "he will tell you to destroy them!" (See: [[rc://en/ta/man/translate/figs-quotations]])