As we have already said, a person is obligated to learn Torah on all four levels. Now, there are only 600,000 souls…

The [souls] all come from the six sefirot.

They correspond to the six days and the six directions of the world. They all come from the six sefirot.

There are stages in the evolution of the descent of the souls into the world. First there were the three patriarchs. Then there were the seventy souls of the house of Jacob (Ex. 1:5). The sixty myriads of souls come next, due to miraculous fertility during the centuries in Egypt.

But don't we see a lot more Jews than six hundred thousand roaming the face of the earth?! How could there be only six hundred thousand? The answer is that each one is like a grand tree root from which stems out many branches/souls. Thus many people in bodies share the same soul root. If you feel especially connected with certain individuals, this is a sign that you share with them a mutual source.

…and the Torah itself is the source of all Jewish souls..

Therefore there are six hundred thousand letters in the Torah (Zohar).

…the place from which they are "hewn."

Each letter is a source and channel for a soul root to evolve from. The sages view this as if a rock hewn from a mountain.

Therefore, there are 600,000 explanations on the level of "Peshat," on the level of "Remez," on the level of "Drash," and on the level of "Sod."

From this we see how important each individual is! Each of these souls has its own original, custom made connection to the four ways of learning. Therefore, no matter how much Torah has already been written, there is always place for you to come along and give the world new ideas!

The Torah and the souls are one.

At root level, the Torah and the souls are one (Zohar).

Thus, for every one of the 600,000 explanations there is one Jewish soul, and in the Time-to-Come each will know Torah according to the explanation that corresponds to the root of his soul. In the Garden of Eden, after a person has died he will understand all of it.

If so, why should one toil to understand the Torah in this world? The answer is, the more one learns and the deeper one understands, the higher level he starts learning at in the after life.

Furthermore, every night when a person goes to sleep he 'deposits' his soul above. The one who merits to ascend above…

Later the Ari enumerates what one can do to gain this privilege.

that day the specific verse 'shone' in him more than other days.

…is taught the explanation upon which his soul-root is based, the extent to which depends upon what he accomplished that day, either a verse or a particular parasha, because that day the specific verse 'shone' in him more than other days.

Since his soul is rooted in that verse , when he accomplishes something positive, it is a reflection and revelation of the verse itself. Thus it says about the words Torah, "they are our life, and we will meditate in them day and night" (Joshua 1:8). One who has eyes can see everything going on around in its root in the Torah. This greatly deepens the consciousness and the level of life.

Another night, a different verse will shine in his soul, based upon his actions that day, always according to the explanation upon which his root is dependent.

Originally a great, awesome light shined that spanned the far-flung ends of creation. G‑d saw that not everyone would be fit to enjoy such a light. He therefore hid it (Breishit Raba 3:6). Nonetheless, a little bit of this light must shine to the world every day, or the universe could not endure (Zohar). Each day is a gift from G‑d and comes to us with its own secrets, derived from the bit of light allotted to the day.

Every night my teacher used to look at the forehead of the students standing before him, on the side upon which his soul dwelled and illuminated…

The soul manifests at different times in different parts of the body.

…and determine which verse shone more in that person. He would then explain a portion of the explanation of that verse, according to that which was relevant to his soul.

Even one who is not himself pure enough to merit to such revelation alone can still benefit from this level through being connected to a true tzadik.

Before the person would go to sleep, he would concentrate on that which was partially explained to him. He would also recite the verse in order that when his soul ascended for the night they (in heaven) would teach him the completion of the explanation. This would purify the soul and allow it to keep ascending to even higher levels, where more would be revealed to him, though his body may not have sensed anything upon awakening.

The Vilna Gaon teaches that there are certain boundless levels of Torah that the soul cannot perceive while clothed in the limiting body. In order to enable the soul to access these levels, G‑d created sleep. The soul leaves the body and is thereby allowed to perceive in its intrinsic, full capacity. Even though this level does not necessarily reach the conscious awareness, the light of it enlivens and invigorates the person to a higher degree of spirituality. Also, if one merits, sparks of what he learned trickle into his daily state of mind.

[Translation and commentary by Perets Auerbach.]