When you march up to attack a city, make its people an offer of peace. If they accept and open their gates, all the people in it shall be subject to forced labor and shall work for you. Deuteronomy 20:10-11
Moses was preparing the people for the time when they would take over the Promised Land—the territory God had promised to them. I don’t understand all of the thinking back then, but I do know this was about giving the land to his people and others would need to leave or serve the Israelites. God’s heart is never to hurt people – but it is always to provide for his children. In baptism God made you his child (or would like to). How wonderful it is to have such a provider.