If the LORD your God enlarges your border, as he has sworn to your fathers, and gives you all the land which he promised to give to your fathers; and if you keep all this commandment to do it, which I command you today, to love the LORD your God, and to walk ever in his ways, then you shall add three cities more for yourselves, in addition to these three.
This is so that innocent blood will not be shed in the middle of your land which the LORD your God gives you for an inheritance, leaving blood guilt on you.