The Request Granted conditionally on their Taking Part in the Conquest of W. Canaan. The assistance rendered by Gad in the conquest of W. Canaan (see Joshua 1:12-18) seems to be referred to in Deuteronomy 33:21. The statement that besides Reuben and Gad the half tribe of Manasseh received from Moses a piece of territory E. of the Jordan (Numbers 32:33) appears to be an anachronism, for Numbers 32:39 implies that the establishment of Manasseh in E. Canaan was effected by settlers who went thither after the conquest of W. Canaan had been accomplished.
Numbers 32:28-33
28 So 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:
29 And Moses said unto them, If the children of Gad and the children of Reuben will pass with you over Jordan, every man armed to battle, before the LORD, and the land shall be subdued before you; then ye shall give them the land of Gilead for a possession:
30 But if they will not pass over with you armed, they shall have possessions among you in the land of Canaan.
31 And the children of Gad and the children of Reuben answered, saying, As the LORD hath said unto thy servants, so will we do.
32 We will pass over armed before the LORD into the land of Canaan, that the possession of our inheritance on this side Jordan may be ours.
33 And Moses gave unto them, even to the children of Gad, and to the children of Reuben, and unto half the tribe of Manasseh the son of Joseph, the kingdom of Sihon king of the Amorites, and the kingdom of Og king of Bashan, the land, with the cities thereof in the coasts, even the cities of the country round about.