§ The Gemara comments: From the fact that the mishna states: When hallel is recited, one can conclude by inference that on Rosh HaShana there is no recitation of hallel. What is the reason that hallel is omitted on Rosh HaShana? Rabbi Abbahu said: The ministering angels said before the Holy One, Blessed be He: Master of the Universe, for what reason don’t the Jewish people recite songs of praise, i.e., hallel, before You on Rosh HaShana and on Yom Kippur? He said to them: Is it possible that while the King is sitting on the throne of judgment and the books of life and the books of death are open before Him, the Jewish people are reciting joyous songs of praise? Rosh HaShana and Yom Kippur are somber days of judgment whose mood is incompatible with the recitation of hallel.

It is not the recitation of Hallel on Chanukah alone that is a Rabbinic ordinance, but rather, at all times - i.e., on all the days that the complete Hallel is recited, [the obligation to do so] is a Rabbinic ordinance.
There are eighteen days during the year when it is a mitzvah to recite the entire Hallel. They are: the eight days of Sukkot, the eight days of Chanukah, the first day of Pesach, and the holiday of Shavuot. Hallel is not recited on Rosh HaShanah and Yom Kippur, since they are days of repentance, awe, and fear, and are not days of extra celebration. The [Sages] did not ordain the recitation of Hallel on Purim, because the reading of the Megillah [serves the purpose of Hallel].

Abba Shaul says: Ve’anveihu should be interpreted as if it were written in two words: Ani vaHu, me and Him [God]. Be similar, as it were, to Him, the Almighty: Just as He is compassionate and merciful, so too should you be compassionate and merciful. In any case, there is no proof from Rabbi Yishmael’s statement with regard to the Paschal lamb that he would say the same with regard to circumcision, as in that case, he might agree that fulfilling the mitzva beautifully justifies overriding Shabbat.

[Our Sages] taught [the following] explanation of this mitzvah:
Just as He is called "Gracious," you shall be gracious;
Just as He is called "Merciful," you shall be merciful;
Just as He is called "Holy," you shall be holy;
In a similar manner, the prophets called God by other titles: "Slow to anger," "Abundant in kindness," "Righteous," "Just," "Perfect," "Almighty," "Powerful," and the like. [They did so] to inform us that these are good and just paths. A person is obligated to accustom himself to these paths and [to try to] resemble Him to the extent of his ability.

Know, as a great principle, that the Essential Self of HaShem-יהו"ה, the Creator, blessed is He, as He truly is, is beyond the comprehension of anyone other than Himself. There are none, even amongst the multitude of the highest angels, who know His place, not to mention the Essential Reality of His Being. Do you not see that the supernal angels declare, “Blessed is the glory of HaShem-יהו"ה from His place,” meaning, “wherever He may be.” If this is true of the supernal beings, how much more is it true of the lower creatures. If so, what is the meaning of all those matters that we read of in the Torah, such as a hand, foot, ear or eye? Know and trust that all these matters, even though they indicate and testify to His greatness and truth; no creature is capable of knowing and contemplating what the matter called hand, foot or ear, and the like, is. And though we are made in His image and likeness, it should not enter your mind that what is meant, is an eye in the actual form of an eye, or a hand in the actual form of a hand. Rather, this refers to inner matters and matters that are the inner of the inner, concerning the truth of HaShem’s-יהו"ה existence, blessed is He; matters from which the source and influence comes out to all that exist according to the decree of HaShem-יהו"ה, blessed is He. However, what that hand is, is not what this hand is, nor are they equal in their form, as it states, “Who can you compare Me to, that I would be his equal.” Know and understand that there is no comparison between Him and us in essence and form. Rather, HaShem’s-יהו"ה intention in the form of our organs is that they are made to be like signposts for hidden, supernal matters that the mind cannot know except in a way of representation, like writing the words, “Reuven the son of Yaakov.” Certainly, neither these letters, nor the form of the words, “Reuven the son of Yaakov,” are his actual form, image and being, but are just a representation, that this written name, “Reuven the son of Yaakov” is a sign corresponding to that known essential self and image who is called, “Reuven the son of Yaakov.” Since HaShem-יהו"ה desired to bestow merit upon us, He therefore created several hidden and revealed organs in the body of man, as a sign for the act of the chariot (Ma’aseh Merkavah-מעשה מרכבה). If a person merits to purify one of his organs, that organ becomes like a seat for the corresponding supernal matter that is called by this name, whether an eye or a hand. The same applies to all the other organs. For example, if a person is careful and guards the sight of his eyes, taking care not to look and see matters of licentiousness, nor any other unseemly and disgraceful things, but rather looks at matters of HaShem’s-יהו"ה holiness and service of Him, his eye then becomes like a seat for that supernal matter that is called the “eye.” The same applies to one’s hand or foot and all his other organs.