וזאת אשר דבר להם אביהם: עתיד אדם אחד כיוצא בי לברך אתכם וממקום שפסקתי הוא מתחיל שנאמר וזאת הברכה
And this is what their father told them: In the future, a man like me will bless you, and in the place I stopped, he will start, and it says “And this is the blessing” — Bereshit Rabba 101
We find that both Yaakov and Moshe blessed the Tribes of Israel. Yet it seems that the blessings given were entirely different. Several tribes like Gad get very short blessings from Yaakov and long ones from Moshe. Others are just the opposite. Yehuda gets a lengthy blessing from Yaakov, but Moshe gives a blessing of only a sentence long. Some tribes get a short blessing both times, and Yoseph is given an expansive berakha both times. It makes sense that Levi, now the tribe of priests, gets a much more expansive blessing from Moshe, but what is going on with the other tribes? What was the main purpose of the blessings anyway?
Abravanel suggests that the answer lies in a midrash from Bereshit Rabba. He explains that Moshe did not just happen to start with the same word with which Yaakov ended his blessing. Rather in every case, Moshe was trying to extrapolate from what Yaakov had said and expand upon it with an additional component relevant to the time. For example, Yaakov blessed Yissachar to be a peace-loving man of the land, and so Moshe added to it by wishing him success in the tents. Yaakov had taken the birthright and kingship away from Reuven, and Moshe blessed the tribe that, if they did not merit an increased role in Israel, then at least they should also not merit a decreased one.
I think this also explains the quantity of each blessing. Certain tribes had circumstances very and roles very similar in the time of Yaakov and Moshe, and did not require much addition. Yaakov had blessed Yehuda with rulership and prominence, and in the time of Moshe, Yehuda was still the prominent tribe. It did not need any help from him on this front, so he only wished them that Gd should hear their prayers and grant them safe travels. Yissachar was destined to remain a quiet tribe and did not take an active role in the conflict, so he only blessed them with continued success in their chosen area.
But other tribes were now thrust to the forefront. Gad was previously given a short blessing about its strength of arms. But now it claimed the entire East side of the Jordan and committed to marching in the vanguard of the Israelite force. Therefore Moshe doubled down on the blessing of strength and added to that a blessing of material success. And to counteract the claim that they had chosen to live outside Israel for simple material reasons, he emphasized that their land was the portion of the lawgiver, his portion, the place where his grave was to be and where he had taught the Torah.
There are a few lessons we can learn here about blessings and preparing one for leadership roles. The first is obviously that blessings and encouragement are important when someone is going to be embarking on a difficult endeavor. The second is that we are always building on what came before, good or bad. Moshe started where Yaakov left off, just as Yaakov had started where Yitzhak had left off before him, and future leaders continue where he left off. The third lesson is that just as one needs to build up someone who needs it, one should not build up someone who doesn’t. Gad needed Moshe’s blessing, so he gave them one. Yehuda did not need a blessing of power or kingship, so he refrained from giving them a second. It might have been tempting, even expected, to give the largest and most powerful tribe the grandest blessing. But Moshe didn’t give assistance where it was expected; he gave to those who needed it. We can do the same.