1. Zohar for All, Pinhas, “The Pouring of Water“, Item 895
This is the meaning of what is written, “You shall have an assembly.” Atzeret means “assembly,” Malchut is where everything is assembled, the receptacle for all the upper lights. “You shall have,” and not another, meaning that the Sitra Achra has no part in it. Rather, you will rejoice in your Master, and He with you. It is written about it, “Be glad in the Lord and rejoice, you righteous ones; and shout for joy, all you who are upright in heart.”
2. Maor VaShemesh, “Intimations of Shmini Atzeret”
Our whole intention on the day of Shmini Atzeret [Eight of the Assembly] is for the Creator to unite with the Assembly of Israel and extend all the upper lights to the kingdom of heaven. The unification is mainly through the Torah, and the Torah and the Creator and Israel are one.
3. Zohar for All, Tikkuney Zohar, Correction No. 13
The Eighth of the Assembly is a celebration in itself. In it is the springing of the Torah, to water the tree that is planted in the garden, and its roots and branches. It is like the cycle of the Earth, in which all the festivals are celebrated.
4. RABASH, Article No. 894, "Simchat Torah” [The Joy of Torah]
It is written in Shaar HaKavanot that Torah is called Zeir Anpin, and if he bestows upon Malchut, it means that Malchut is already fit to receive the abundance. Therefore, Zeir Anpin, who is called “Torah,” is happy.
This is called “the joy of Torah.” We can interpret this according to what Baal HaSulam said, that one should be happy that the Creator is happy that He can bestow upon the lower ones.
5. RABASH, Article No. 18 (1987), "What Is Preparation for Reception of the Torah? – 1"
We must remember the known rule that there is no light without a Kli [vessel]. That is, there cannot be filling without a lack. It is impossible to enjoy something without yearning for it, and yearning for something is called “preparation,” meaning a need. The need for something determines the yearning, and the level of the pleasure corresponds to the level of the yearning.
It therefore follows that prior to the giving of the Torah, there had to be a preparation for the reception of the Torah. Otherwise, there could not be joy of the Torah. That is, they had to prepare the need to receive the Torah, and the need yields the above-mentioned yearning. According to the level of the yearning, so is the measure by which we can enjoy the Torah.
6. Baal HaSulam, Shamati, Article No. 242, "What Is the Matter of Delighting the Poor on a Good Day, in the Work?"
When one receives an illumination from above, even while one has not been purified, if he takes this illumination in order to raise himself from his lowliness and approach bestowal, it is considered that the Lo Lishma brings him Lishma, meaning that he is walking on the path of Torah.
This is called “One who is happy on holidays.” A holiday is a good day. And certainly there is no greater good day than when some illumination shines for a person from above, which brings him closer to the Creator.
7. RABASH, Article No. 22 (1985), "The Whole of the Torah Is One Holy Name"
During the study we must always pay attention to the purpose of the study of Torah, meaning what we should demand from the study of Torah. At that time we are told that first we must ask for Kelim, meaning to have vessels of bestowal, called “equivalence of form,” by which the restriction and concealment that were placed on the creatures are removed. To the extent that this is so he begins to feel the holiness and begins to have a taste for the work of the Creator. At that time he can be happy because Kedusha [holiness] yields joy, for the light of doing good to His creations shines there.
8. RABASH, Letter No. 36
If a person wishes to do plentiful good deeds and study of Torah, but cannot, he should not regret it but be happy while working in the right. He should be content with whatever he can do, and praise and thank His name for being able to do a small service to the King. Even a minute a day or a minute in two days should be to him like finding a great treasure.
And even if it is a simple deed, meaning without vitality, he should still try to be happy and derive vitality from being allowed to serve the King. This is how he should be during the study, meaning whole. This is regarded as Torah, which is right, as it is written, “On His right was a fiery law.” For every opportunity, one must praise the Creator.
9. Baal HaSulam, Shamati, Article No. 58, "Joy Is a ‘Reflection’ of Good Deeds"
Joy is a “reflection” of good deeds. If the deeds are of Kedusha [holiness], hence joy appears. However, we must know that there is also a discernment of a Klipa [shell]. In order to know if it is Kedusha, the scrutiny is in the reason. In Kedusha, there is reason, and in the Sitra Achra [other side] there is no reason, since another god is sterile and does not bear fruit. Hence, when gladness comes to a person, he should delve in words of Torah in order to discover the mind of the Torah.
10. RABASH, Article No. 12 (1989), "What Is a Groom’s Meal?"
If a person, while receiving the pleasure from the Creator, tries to delight the King by receiving in order to bestow upon the Creator, and his joy is from trying to aim to bestow contentment upon his Maker, by this he obtains a Kli [vessel] of bestowal with which he delights the Creator because the purpose of creation is to do good.
This delights the Creator, since now the Creator can give delight and pleasure to man, since man is now able to receive in order to bestow. Then the verse “The Lord delights in His works” comes true, meaning with the work of creation, for His will is to do good to His creations.