And it is connected with that which was said, that man is required to occupy himself with the Torah on its four levels. And this is it: You should know that the sum of all souls is 600,00 and no more. But behold, the Torah is the root of the souls of the Jewish people, for they were hewn from it, and they were implanted in it. And hence there are 600,000 explanations in the Torah, all of them according to the straightforward meaning [peshat], 600,000 in hints [remez], 600,000 in exegesis [derash], and 600,000 in the esoteric teachings [sod].
So it comes out that every soul in Israel is made from one of the 600,000 explanations. And in the future to come, each and every Jew will grasp knowledge of all of the Torah according to that explanation which is directed to the source of his soul, through which it was created and made, as mentioned above. And likewise, in the Garden of Eden, after a man's death, he will grasp all this. And so too, every night when a person sleeps and deposits his soul and it exits [his body] and ascends above, there they teach that explanation that the root of his soul depends upon to whoever merits to ascend.
Of course, everything is according to his deeds that day — according to that, will they teach him one verse or a certain section that night, so that verse will be clearer to him then than on other days. And on a different night, another verse will be clarified to his soul, according to his deeds on that day. But all of them will be according to that explanation upon which the root of his soul depends, as mentioned.
And my teacher [Ari], may his memory be blessed, would gaze at his students standing before him each evening and see which verse was shining more on his forehead from the angle of the residence of his soul shining there. So he would clarify something of the explanation of that verse according to the explanation relevant to his soul, as discussed. And before that man would sleep, he would have this explanation, which he explained a little, in mind and would read this verse orally so that when his soul ascended above as a deposit during his sleep, they would teach him the rest as well.
And the soul is purified through this and ascends countless great levels; and other things would be revealed to it, even if [his] physicality would not notice it when he awoke. And it has already been explained that the 600,000 explanations of the Torah are all according to the straightforward meaning, and likewise corresponding to them in the Aggadah [homiletical teachings], and likewise corresponding to them in the Kabbalah, etc. which are hinted to in the initials, PaRDeS.
That is because there is no soul in Israel that is not made up of these four aspects. Of course, there will be a soul in Israel that, grasps two types of understandings, and there are those [with] more and more. So behold, our teacher Moses grasped all 600,000 explanations of the Torah. And it is like the rabbis, may their memory be blessed, said — that he knew even that which a senior student would develop in the future.
And the reason for the thing is because his soul included all of the 600,00 souls of Israel. And therefore even the other sages of Israel grasped many explanations of the Torah, according to the aspects of the souls included in him.