Why does it mention the inheritances of the two halves of Menasheh?
Radak: It explains how it was that half of Menasheh was with Gad and Reuven.
Malbim: Refer to 22:7:2:4.
The previous verse said that Yehoshua sent them and blessed them. Why is this repeated?
Rashi: It teaches that he sent Chetzi Menasheh, just like he sent Gad and Reuven. 1
Radak: It was repeated to put this next to the great wealth that he sent with them (after interrupting to teach why Menasheh was split).
Radak citing Bereishis Rabah 35:3: After they received permission to leave, they returned after two days and asked permission a second time.
Malbim: Because Menasheh was divided, they needed an extra Brachah by themselves.
Malbim (8): Chetzi Menasheh in Ever ha'Yarden needed to delay to divide with the half in Eretz Yisrael proper, so they left after Gad and Reuven; Yehoshua sent and blessed them when they were ready to leave.
Radak: This is somewhat difficult, for the previous verse applies also to Chetzi Menasheh.