Numbers 32:20–28

²⁰And Moses said to them, If ye do this thing, if ye arm yourselves before Jehovah for war, ²¹and all of you that are armed go over the Jordan before Jehovah, until he have dispossessed his enemies from before him, ²²and the land is subdued before Jehovah, and afterwards ye return, ye shall be guiltless toward Jehovah and toward Israel, and this land shall be your possession before Jehovah. ²³But if ye do not do so, behold, ye have sinned against Jehovah, and be sure your sin will find you out. ²⁴Build yourselves cities for your little ones, and folds for your flocks, and do that which has gone out of your mouth. ²⁵And the children of Gad and the children of Reuben spoke to Moses, saying, Thy servants will do as my lord commands. ²⁶Our little ones, our wives, our cattle, and all our beasts shall be there in the cities of Gilead; ²⁷but thy servants will pass over, every one armed for war, before Jehovah to battle, as my lord says.

²⁸So concerning them Moses commanded Eleazar the priest, and Joshua the son of Nun, and the chief fathers of the tribes of the children of Israel.