Avenge the children of Israel of the Midianites: afterward shalt thou be gathered unto thy people.
Avenge the Israelites on the Midianites; afterward you shall be gathered to your [departed] people.
Take just reparations for the Israelites from the Midianites. Afterward you will join your ancestors.
"First, avenge the sons of Israel from the Midianites, and then you shall be gathered to your people."
Revenge first the children of Israel on the Madianites: and so thou shalt be gathered to thy people.