We read in Parshat Matot, Bamidbar 32:1: “The children of Reuven and the children of Gad had abundant livestock-very great. They saw the land of Yazer and the land of Gilad, and behold! The place was a place of livestock.”
The tribes of Reuven and Gad ask Moshe, Elazar HaKohen and the leaders of the assembly if they can inherit the lands in Transjordan rather than cross the Jordan and inherit with the rest of B’nai Yisrael. Moshe is not happy about this because it reminds him of the Meraglim (scouts) who did not want to inherit the Land of Israel. He is also afraid that in times of war, they will abandon their brothers who will have to fight on their own. They therefore make an agreement that the tribes of Reuven and Gad will inherit in Transjordan but they will come to fight the wars on the other side of the Jordan as pioneers.
All of a sudden in Bamidbar 32:33, we see that part of the tribe of Menashe is also included: “So Moshe gave to them- to the children of Gad, and the children of Reuven and chatzi (half of) the tribe of Menashe son of Yosef- the kingdom of Sichon king of the Emori and the kingdom of Og king of Bashan the land with its cities in the boundaries, and the cities of the surrounding land.
How did part of the tribe of Menashe end up being included?
According to Degel Machane Ephraim (Moshe Chaim Ephraim of Sudilkov), Moshe wanted to bridge the two tribes on the east bank (who would otherwise be isolated) with the rest of the nation. By placing half of Menashe on the east bank, they would serve as a link to their brothers and the other tribes on the other side of the Jordan and would provide the opportunity for the tribes of Reuven and Gad to connect to the holiness of the Land of Israel.
In verses 39-42 we read about the tribe of Menashe’s role in capturing the area: “The children of Machir son of Menashe went to Gilad and captured it, and drove out the Emori who were in it. Moshe gave the Gilad to Machir son of Menashe and he settled it…”
In Yehoshua, 17:1 we also read about the inheritance of Menashe’s family: “Then came the lot for the tribe of Menashe, for he was Yosef’s firstborn, for Machir the firstborn of Menashe, the father of Gilad- because he was a man of war- therefore he had Gilad and Bashan.
According to Abarbanel, since Machir’s family consisted of powerful fighting men, the Machirites volunteered to settle east of the Jordan in order to defend the area against foreign invaders. They did not settle there for economic reasons as we don’t see that they had extensive flocks like the tribes of Reuven and Gad.
The Jerusalem Talmud, Bikurim 1:8 explains that the members of the tribe of Menashe received a territory in the northern part of Transjordan that had always been designated for them.
Ramban points out that that the word chatzi usually means half, but it can also mean part, as it does in the case of the tribe of Menashe, as only two (Machir and Gilad) out of Menashe’s eight families settled on the east bank of the Jordan.
It turns out that the tribe of Menashe ended up with the biggest inheritance out of all of the tribes. Malbim explains that by Menashe receiving portions on both sides of the Jordan, it was as if he was given a double portion- which would be befitting as he was Yosef’s firstborn.
In the case of Menashe, the oldest son of Yosef earned the largest inheritance, while in the case of Reuven, Yaakov’s oldest son, the firstborn lost out by choosing to abandon his inheritance on the eastern side of the Jordan, in the Land of Israel.