"You are standing today, all of you, before Hashem, your G-d: Your heads, your tribes, your elders, and your officers-all the men of Israel" (29;9).
However, the tribes included all the heads-so why did the torah need to write both "your tribes" and "your heads"?
Rashi (29;9) explains that the torah means to say "your heads TO your tribes." Meaning, they are all one group.
However, why didn't the torah simply write the word "Rasheichem" (meaning: your heads) without the last 2 letters ("chuf" and "mem")-it would still mean the same exact thing ("your heads")!?! There are no extra letters in the torah. If the torah could have said the same exact thing with a shorter word then why didn't it?!?
Rabbi Yochanan Zweig explains that what the torah means to say is that the heads were a combined effort of everyone from the tribes. Meaning, it was only through the tribes that the heads were able to be successful at their high positions. Similarly, Rabbi Zweig explains that people who are leaders of large groups need to realize that they are only able to hold their position because of all the people below them. All leaders have a responsibility to share their accomplishments with those who help them as it is only through the help of others in which one could become "a head." Therefore, the torah wrote "your heads, your tribes" in order to teach us that the heads were an expression of the tribes as it was only through the tribes in which "the heads" were able to become "heads."
We could now also understand what Rashi (29;9) meant by saying "your heads to your tribes." Rashi is saying that the heads were a reflection of the tribes, as all the success of the heads was only made possible through the tribes.
Rabbi Zweig explains that we could learn from here a very important message regarding raising our children. Often times in families there is one child which rises above all the rest like a superstar. Naturally, this leads to jealousy from all the other kids. For such a situation the torah here is teaching us that we should plant the message the minds of our children that we are all one group and no one could be the leader of without help from others. Therefore, if one child rises higher than the rest the focus should remain on everyone as a whole-as it is only with the help of one's family in which one could become a leader in their home.