Numbers 32:21-23

Amplified Bible

²¹ and every armed man of yours will cross the Jordan before the Lord until He has driven out His enemies before Him, ²² and the land [west of the Jordan] is subdued before the Lord, then afterward you shall return and be blameless [in this matter] before the Lord and before Israel, and this land [east of the Jordan] shall be yours as a possession before the Lord. ²³ But if you do not do this, behold, you will have sinned against the Lord; and be sure that your sin will find you out.