The uniqueness of the soul of Moshe: 

While the 600,000 souls of the Jewish people are compared to the feet of the nation, Moshe is the head of the nation. The reason for this is because the soul of Moshe even after its descent below shines as it did above. It does not go through the descent and transformation from the status of head to the status of feet as occurs to all other souls. This means that the same level of revelation that the soul of Moshe experienced above in heaven in the world of Atzilus, it experiences likewise below within his body. The reason for this is because Moshe as well as the forefathers were chariots for G-d, being completely nullified to Him. This is in contrast to all the other Tzadikim, that although they too retain a very holy soul, nonetheless it goes through a state of descent and transformation to the point that it is not of the same level as it existed in the world of Atzilus. 

Intellect is found more in the hands than in the feet:

It is readily evident that one’s hands contain a greater revelation of one’s intellect than one’s feet. This can be seen during times of joy that one’s hand automatically clap in expression of joy, in contrast to one’s feet which will only dance upon instruction from the brain. The reason for this is because although both the arm and legs are completely nullified to the head, nonetheless, the arm is considered like an extension of the head, while the legs are considered more independent and need to listen to the commands that come from the head. This is the difference between the souls of Moshe and the forefathers, in contrast of the souls of the other Tzadikim. Moshe and the forefathers are similar to the hands of the body which are absolute chariots to the head, in contrast to the other Tzadikim who are similar to the legs which are separate entities and need an instruction and command in order to listen.