במדבר לב, א : אִם-יִרְ אוּ הָאֲנָשִים הָעֹלִים מִמִצְרַיִם מִבֶׁן עֶׁשְרִ ים שָנָה וָמַעְלָה אֵּת הָאֲדָמָה אֲשֶׁר נִשְבַעְתִי לְאַבְרָהָם לְיִצְחָק וּלְיַעֲקֹב כִי לֹא-מִלְאוּ אַחֲרָי:
Baal HaTurim notes that in this incident bnei Gad and bnei Reuvein are mentioned eight times (seven times together and once each by themselves). This alludes to the fact that when the bnei Yisrael later went into exile the bnei Gad and bnei Reuvein were expelled eight years earlier than the rest. Baal HaTurim goes on to say that in Mishlei 20,21 the verse says, "Nachaloh m'vo(c)helles borishonoh vaacharisoh lo s'voroch." The word "m'vochelles" is written with a Ches, but is read with a Hei. With a Ches the meaning is, "An inheritance that is originally seized and its outcome will not be blessed." With a Hei it means, "An inheritance that is originally gotten impetuously and with haste and its outcome will not be blessed." It is written with a Ches (numerical value of eight) to again allude to the eight times they are mentioned in the Torah in this incident. The reading with a Hei means impetuously and with haste, and this is what happened to them, they were exiled earlier than all the other tribes.
When Moshe negotiated with them he asked for them to cross into Canaan and join in the war against the 31 kings and to not return until the land was vanquished. They counter-offered even better, that they would even stay on until the land was apportioned to each tribe. This extended their mission by seven years and Yehoshua praised them for keeping to all the terms of the agreement (Yehoshua 22:2,3). If so, why were they criticized in Mishlei and sent into exile eight years earlier? There was much give and take regarding when they would take actual ownership of their Trans-Jordanian lands, with them wanting to do so immediately, and Moshe insisting that it not take place until after Eretz Yisrael was vanquished. They did not let up and Moshe, to avoid ongoing arguments, gave in. Their insisting that they take immediate position was a slight to the sanctity and importance of having heritage land in Eretz Yisrael, and for this they were sent out earlier.
