Numbers 32:17

32:17 but we will maintain ourselves in armed readiness and go before the Israelites until whenever we have brought them to their place. Our descendants will be living in fortified towns as a protection against the inhabitants of the land.

Numbers 32:33

Land Assignment

32:33 So Moses gave to the Gadites, the Reubenites, and to half the tribe of Manasseh son of Joseph the realm of King Sihon of the Amorites, and the realm of King Og of Bashan, the entire land with its cities and the territory surrounding them.