Why were seven Shevatim remaining?
Rashi: Gad, Reuven and half of Menasheh already received in the days of Moshe, and Yehudah, Efrayim and the rest of Menasheh already received 1 via lottery in the days of Yehoshua.
Malbim: Yehudah and Yosef received first, because Mashichim will come from them.