Messengers: The term Malach means emissary, as angels are considered messengers of Hashem.
Similar to animal kingdom: Angels are called animals, domestic and wild, as the verse states “And the face of the lion to the right, and the face of the ox to the left.” The reason for this is because similar to animals, angels do not contain freedom of choice, and their emotions are natural and instinctive. Their love and fear of G-d is not generated anew as a result of comprehension, but rather comes as an instinctive part of their nature. It is for this reason that Tzaddikim are considered to be of a higher level than angels. However, there are select angels who have the unique capability of intellectual thinking and process, hence being able to develop innovative love and fear that comes as result of comprehension.
Worlds of existence of angels: The abode of majority of angels is in the world of Yetzira. The reason for this is because the world of Yetzira corresponds to the emotional attributes of the angels which is the highest level that they can reach in service of G-d, expression of their natural inborn emotions. However, there are select angels whose abode is in the higher world of Beriya. These angels have the unique capability of intellectual thinking and process, hence being able to develop innovative love and fear that comes as result of comprehension.
In which world is Machaneh Michael/Garviel/Rafael found: In each world of Beriya, Yetzira, and Assiya the four camps of angels exist. The camp of Michael, who is a camp of myriads of angels led by the arch angel Michael, exists in Beriya, and a second camp exists in Yetzira, and a third camp exists in Assiya. The same applies by the other camps of angels, that they have camps in each world.
Birth and death within prayer: Many myriads of angels die and are reborn within their daily praise of G-d. They burn within the great revelation of G-dliness which arouses within them a boundless feeling of passion and G-d then revives them. This is the meaning of the verse “Yotzer Mesharsim”, that Hashem recreates his servants, his angels. [Angels pray just like man below, however their prayer involves a revelation of G-dliness which they vividly experience. However, this revelation is too much energy for them to handle and they thus experience an expiry of their soul, and cease to exist as a soul and body. This mainly occurs during the recital of Kadosh Kadosh Kadosh in the blessings of Shema. Hashem however then revives the angels to serve him again.]
Bodies: Angels have bodies. This is called their Ruach. The bodies are made of Ruach and Eish. It is because they have bodies that they are able to have their voice heard, an actual physical voice. Likewise they can invest themselves in bodies and be seen in bodies as is seen with Avraham. This is opposed to souls which have no body and hence they have no audible voice and cannot be seen. Angels need to have their bodies/Chomer refined through song. Toras Menachem 1:30
Desire to receive Torah: The angels desired to receive the Torah over man. Why? As although they knew that the Jewish souls are higher than the angels they felt that they have a body while the souls do not have a body in it if themselves, and hence it is more befitting that they the angels receive the Torah which has descended. Now, although the souls also became invested within the body, nevertheless such a body, the angels claimed, will overcome the soul and cause it to sin. Hashme answered them that he specifically desires a Dira Betzachtonim with physical bodies, and only the souls when they are within physical bodies can accomplish that.
The gender of angels-Male versus female: In Kabala it states that there are angels who come from the level of Za and angels who come from the level of Malchus. Angels who come from Z”a have a masculine aspect, while angels who come from Malchus have a feminine aspect and are called daughters and Nukvin. However, in the Midrash and Poskim it states that there are no female angels and all angels are male. This is learned from the verse “Ir Giborim Ala Chacham” which means that Moshe ascend to the city of angels, and these angels are called Gevarim, thus proving that there are no female angels. Based on this it is ruled in Halacha that women are not to wear white clothing on Yom Kippur to emulate angels, as they cannot be like angels, as angels are only male.
The purpose of the female angels: Kabala explains that the purpose of the feminine angels who derive from Malchus is to discern the sins committed by people of the world. The Sefirah of Malchus has the function of judging the world, and hence requires information of the acts of the worlds inhabitants. Hashem set up the system in a way that the Sefiros do not automatically know the actions of the creations and need messengers to deliver the information to the Sefiros. This is the function of the female angels; they elevate news regarding the creations to the Sefirah of Malchus. They also carry the blemish caused by sin of the creations into the Sefira of Malchus. On this the verse states “Einei Hashem Mishotetos” in female tense.
Do angels eat? Just as humans and animals require food to survive, similarly angels require spiritual food and sustenance for their existence. The spiritual food of the angels is the light of G-dliness that shines towards them from above. This spiritual sustenance eventually becomes the source of physical food.
Angels of each level: There are angels in Asiya, Beriya and Yetzira.
The cry of the angels after the Churban: The destruction of the Temple did not just affect the Jewish people here below, but effected also all the creations found in the supernal worlds of angels and souls. Prior to the destruction, the spiritual beings enjoyed a superior revelation of G-dliness that derived from the unity found in the Sefiros of Za/ז”א [Zeir Anpin, the male aspects of the Midos] and Nukva [Malchus, the female aspects of the Midos], called Zun/זו”נ. The destruction of the Temple however caused a break of this unity, which consequently affected the revelation of G-dliness experienced by the spiritual beings and angels. The angels could no longer receive the revelation that they once experienced, and this caused them tremendous pain and anguish. On this the verse states “The angels of peace cried bitterly”, as they cried on the loss of their revelation.
Mitzvos: Angels are not obligated and are not able to fulfill Mitzvos. The reason for this is because they do not have an evil inclination. It is the animal soul of a Jew which makes Mitzvos have the power of drawing down G-dliness. The explanation is as follows: Mitzvos involve matters in the physical world. For a Mitzvah to draw down G-dliness towards these physical items it needs to be prefaced with a subjugation of the animal soul. The subjugation of the animal soul [Iskafya] refines and elevates the Kelipas Noga, and elicits the Hamshacha of G-dliness above which is drawn into the Mitzvos. Since angels don’t have an animal soul which they can subjugate, they are unable to draw G-dliness into the Mitzvos.
Standers versus walkers: Angels are refered to as “Omdim/standers” in scripture in contrast to “Mehalchim/Walkers” which is used in reference to man. This matter is not a mere play on words, but a description of difference between man and angels. Standing connotes one’s still position, not moving either backwards or forwards. In service of G-d this means that the angels retain an equal fom of Divine experience throughout their existence. They never develop a greater or different experience of G-dliness than that which they are capabale of naturally handling. However, man is defined as a walker, as walking connotes constant change of position. Man has ability to exceed his natural limitations of G-dly experience and grow to receive even more than the angels. This power of spiritual wlaking is only found in souls that are invested in bodies in the physical world. The souls of man as they are found in the spiritual woprlds, such as Gan Eden, are aslo considered “Standars” just like the angels. The ability to expand one’s G-dly experience to levels that are infinitely greater than one’s natural capacity is a result of the investment of one’s G-dly soul into the animal soul and body which are rooted in Tohu and G-d’s essence. It is the Torah and Mitzvos performed in this world in a phsycial body with Iskafya and Ishapcha that give man the ability to grow beyond the levels of angels or even his own soul as it existed prior to its descent.
Sweat of the angels: The angels release spiritual sweat from their great fear and trepidation of G-d which they experience. This sweat is the source of the water of the river called Nehar Dinor. This river is found between spiritual worlds, and serves as a cleansing pool for sinners. This sweat, as all sweat, is the waste of the angels, and is the anger that derives from Kedusha, an anger towards Reshaim who oppose and rebel against Hashem. This is why their sweat serves to create the Dinar river, and is a cleansing pool for Reshaim, a form of Gehinnom.
Hadarniel: Is higher than all other angels 1,600,000 Parsaos. He walked with Moshe to Sandalfon.
Sandalfon: Is higher than all other angels, including Hadarniel. He creates crowns for Hashem from prayers of the Jewish people, and then Hashem accepts their prayers. Moshe went to him with Hadarniel to accept the Torah.
How long do angels live for? There exist two types of angels, one called Beni Elokim, and the second called Bnei Eilim. The angels of Bnei Elokim, are angels that were created during the six days of creation, and they do not die or expire. They have been serving G-d since that time without fail. The second type of angel, Bnei Eilim, is angels with a lifespan of a mere few hours. They are created daily, in the morning, for the purpose of singing praise to Hashem, and expire within this process of singing. These two forms of angels are hinted to in the daily prayer of Birchas Shema in which we recite “Veyotzer Mesharsim Veasher Mesharsav”; the term Yotzer Mesharsim refers to the angels that are created daily while the term Veasher Mesharsav refer to the angels that live forever. The temporary angels derive from the level of Desha, which means plantation, as they are similar to plants which grow daily from the earth. These angels of Bnei Eilim are the angels that are found in the world of Assiya.
Saying the name of an angel: The Arizal was very careful not to mention the name of angels in his speech, such as upon giving a Torah Drasha, and considered it a prohibition. Rather, he would say the initials, such as Mem Tes instead of Matatron, and when he desired to mention Samael, he would say Samech Mem. It is however permitted to mention the name of Michael and Gavriel, and of any other name that is used amongst people for naming their children. [Likewise, it is seemingly permitted to mention the name in the midst of a prayer or supplication.]
The name Samael: One who mentions the name of the angel called Samael, transgresses the prohibition of “Visehim Elokim Acheirim Lo Sazkiru.”
The difference between the service of man versus angels: The angels are referred to as animals, both wild [Chayos] and domestic, as the verse states “Upnei Aryeh El Hayamin, Upnei Shur Mihasmol.” The reason for this is because the angles do not have freedom of choice, and their love and fear is naturally born with them as written in the Raya Mihemna Parshas Pinchas. It is for this reason that the Tzadikim reach higher levels than the angels, as is seen from the fact that the abode of the Tzadikim in the upper world is in the world of Beriya, while the angels dwell in the world of Yetzira. *This, however, only refers to the regular angels called Chayos Tiviyim. However, there do exist angles called Chayos Sichliyim which reside in the world of Beriya, as their Avoda is to serve Hasehm with intellectual love and fear. [To properly understand why the Tzadikim dwell in Beria while the angels in Yetzira, we must first introduce the difference between the two worlds.]
 Siddur Im Dach p. 309a
 Tanya chapter 39 [p. 51b]
 Admur ibid in Hagah
 Tanya chapter 39 [p. 51b]
 Siddur Im Dach p. 309a
 Likkutei Torah Seitzei 34b
 Likkutei Torah Vezos Habracha 98a
 Likkutei Torah Vezos Habracha 98a
 Torah Or Vayeira 15a based on Zohar Mishpatim p. 107
 Yalkut Simoni on Mishlei 21/22 brought in Machatzis Hashekel 610/5
 Admur 610/9; M”A 610/5; Mateh Moshe brought in Machatzis Hashekel ibid
 Mishlei ibid
 Yalkut ibid
 Admur ibid; M“A ibid
 Torah Or Vayeira 15a
 Divrei Hayamim 2 16/9
 Likkutei Torah Parshas Tzav 7b
 Tzav 7b
 Likkutei Torah p. 12b
 Torah Or Toldos 18a
 Torah Or Vayeishev 30a
 Torah Or Vayeishev 30b; Siddur Im Dach p. 309a
 Likkutei Torah Pinchas p. 79b
 Custom of Arizal, as brought in Shaar Hamitzvos, Nagid Mitzvah in Seder Hakeria, Shaar Hakavanos Drush Alef Tefilas Arvis; Shelah p. 100; Zechor Leavraham 3 Mareches Habayis; Kaf Hachaim 5:10
 See regarding the statement of Zevadya Yishmireini, said on Rosh Chodesh after Hallel: Siddur Admur; Siddur Rav Shabsi [student of Baal Shem Tov] and Rav Yaakov Kopel [brought in Shaar Hakolel 37:9]; Mishnas Chassidim Rosh Chodesh 2:1 [1700’s]; Sefer Chemdas Yamim [1700’s]; Machberes Hakodesh [Harav Nassan Shapiro-1600’s] Shaar Rosh Chodesh in name of old manuscript; Kaf Hachaim 422:57; It is omitted in Siddur Harizal and in Peri Eitz Chaim [Shaar Hakolel ibid] Zevadya is the name of an angel. Some are accustomed not to recite the names Zevadya due to the prohibition in reciting the name of angels. Hence, they say this word in their mind. Nevertheless, Admur writes “And he should say Zevadya..” in order to emphasize that one is specifically to verbalize it. This allowance is seemingly due to that it is also the name of a person in Tanach. [Shaar Hakolel 37:10; See Nefesh Chaim [Falagi] 32] ALikkutei Torahernatively, the prohibition of mentioning the name of an angel only applies if one does so for no reason, while if one does so as part of prayer, it is permitted. [See Kaf Hachaim 5:10 that the Arizal would not mention the angels in middle of a “Drasha”] Some Siddurim however avoid this issue by replacing the name Zevadya, with the name of Hashem.
 Shaar Hamitzvos Parshas Mishpatim; Kaf Hachaim ibid
 Tanya Chapter 39