What are "Omedim"?
Targum Yonasan: Kadishim. Radak - i.e. Kadosh angels that exist forever.
Kli Yakar (Vayikra 18:4): Angels remain at one level, unlike man, who goes from level to level.
Malbim: This refers to miraculous conduct. It is not fixed; the Serafim are prepared for when they will be commanded.
Why does it say "mi'Ma'al Lo"?
Rashi, from Targum Yonasan: They stand above, in Shamayim. "Lo" teaches that they are to serve Him.
Radak: They are near Him. Also 'Al' means near, like "v'Alav Mate Menasheh" (Bamidbar 2:20), "v'Zavachta Alav" (Shemos 20:21).
Malbim: This refers to miraculous conduct. It is above the Kisei; it moves the Kisei, i.e. the Ma'arachah.
Here it says that each has six wings. In Yechezkel (1:6), it says that each has four wings!
Radak: Yechezkel saw four, for there are four reasons for motion; so says Moreh ha'Nevuchim 1 . Wings are for flying, which is the fastest motion. Yeshayah mentioned [all] what is seen (unlike Yechezkel, who counts the reasons for motion, which are not seen - PF).
Radak citing Chagigah 13b: While the Mikdash stands, each has six. When it is destroyed, it is as if the wings of the Chayos were diminished.
Radak: Here it discusses Serafim; their faces and feet are hidden (so they have four wings in addition to the two for flying). Yechezkel discusses Chayos; they have two wings to hide their bodies, and two for flying. The wise understand this secret.
Malbim: 'Kenaf' has three meanings. (a) The end and border - Kanfos ha'Beged. (b) Hiding and covering - "Lo Yikanef Od Morecha" (30:20). (c) [Wings for] flying. Each of their three pairs of wings hints to one of these - refer to 6:2:4:3, 6:2:5:3, 6:2:6:1. There are two wings for each, and not just one, to teach that even though they are not physical, they are not unities like their Creator.
Radak: Only two are for flying. The others are to cover!
Why does the angel cover his face?
Rashi: This is lest he look towards the Shechinah.
Targum Yonasan: It is lest he see. Radak - his Perush helps us understand that this vision was purely intellectual. Serafim do not have faces, feet or wings, like the philosophers and Rambam say. They are called Serafim, for Yeshayah saw a fire burning, to show the generation's sin; they deserved to be burned.
Malbim: This shows that they have a limit and size. Even though they do not have an external (physical) limit, for they are not physical, they have an internal limit, i.e. their strength, for they are outcomes of a Cause. There are two, and not one - the increase shows that they receive influence and life from a Cause above them. They understand themselves and their Cause.
Malbim (3): They recognize that Hashem is forever; He is above their understanding, and they have no connection with Him.
Why does the angel cover his feet?
Rashi: This is for modesty, lest his entire body appear in front of his Creator.
Rashi citing Tanchuma (Emor 11): The soles of his feet are like of a calf (Yechezkel 1:7); they are covered, lest this recall Yisrael's sin of the Egel.
Malbim: This shows that their essence is hidden; we do not understand it. Man understands only matters to which time and place apply. Their feet move them; also these are covered. There are two, to show that they have power, and influence on others 1 .
Malbim (3): They recognize what they influence below, and know that Hashem's honor is also there, and He is separate from all.
Malbim: Also our tradition teaches that there are angels that cause and are caused, influence and receive influence. Also ancient Greek philosophy taught so!
What is "Ye'ofef"?
Rashi citing Targum Yonasan: He serves. Malbim - i.e. they fly (run) to do the will of their Maker. There are two, to show two aspects - they themselves exist, and their purpose is to do their Creator's will.
Malbim (3): They recognize themselves, and realize that Hashem is greatly elevated above them.
