[S. Bamberger]
The words Demut - likeness - and Mar'eh - appearance - are insisted on again and again... the prophet wants to make clear that... what he has seen... can be represented only by analogy.
As the vision proceeds, it becomes progressively difficult to sort out visually what these creatures and the moving composite they make up, look like... A certain bewilderment may well have been Ezekiel's intention...
This four-sided moving structure, with wheels below and a kind of platform above, is what led tradition to call it a "chariot," Merkavah. To moderns, it may seem like a bizarrely composite hovering helicopter.
[Robert Alter]
(א) כיוון איבריו בשעת תפלה. יכוין רגליו זה אצל זה בכוון כאלו אינם אלא אחד להדמות למלאכים דכתיב בהן ורגליהם רגל ישרה כלומר רגליהם נראים כרגל אחד: (וי"א כשעומד להתפלל ילך לפניו ג' פסיעות דרך קירוב והגשה לדבר שצריך לעשות) (רוקח):
(1) The Position of One's Limbs at the Time of Prayer One should position one's feet next to each other as though they are one, in order to imitate angels, as it written regarding them: “their feet were a straight foot” [(Ezekiel 1:7)], which is to say their feet appeared as one foot. (Some say when one stands to pray one should take three steps forward in the way of coming close and approaching a matter that must be done.) (Rokeach)
אָמַר רָבָא: כׇּל שֶׁרָאָה יְחֶזְקֵאל, רָאָה יְשַׁעְיָה. לְמָה יְחֶזְקֵאל דּוֹמֶה — לְבֶן כְּפָר שֶׁרָאָה אֶת הַמֶּלֶךְ, וּלְמָה יְשַׁעְיָה דּוֹמֶה — לְבֶן כְּרַךְ שֶׁרָאָה אֶת הַמֶּלֶךְ.
§ Rava said: All that Ezekiel saw, the prophet Isaiah saw as well, but the latter did not find it necessary to describe his vision in such detail. To what may Ezekiel be compared? To a villager who saw the king and is excited by all the extravagances of the king’s palace and everything it contains, as he is unaccustomed to them. And to what may Isaiah be compared? To a city dweller who saw the king. Such an individual focuses on the encounter with the king, and is oblivious to all the distractions.
(ב) טוב לכוין רגליו בשעה שאומר קדושה עם שליח ציבור. הגה: ויש לישא העינים למרום בשעה שאומרים קדושה וכן מנענעים גופן ונושאין אותו מן הארץ...ומי שאמר סדר קדושה ובא לבית הכנסת ומצא צבור עונין קדושה חוזר ועונה עמהם (תשובת הרשב"א סימן רמ"ט):
It is good to put your feet together in the time that you say Kedushah with the Chazan. Ramah: And there are those that lift up their eye to the heavens in the hour that they Kedushah and they shake their bodies and lift up from the ground...(The Rashbah says) one who already said Kedushah and came to Synagogue and found the congregation saying Kedushah should return and answer with them.
And You have established in glory and praise a magnificent song of praise And all the angelic legions and Seraphim standing before You Praise and glorify Your Name And the wheels of the Chariot utter song before you And You have established Your Throne of Glory, song and merit, and the ministering angels that stand and sanctify the holiness of Your Name Extol Your might And say, YHWH of Hosts, Shaddai, YHW, lives for ever. Your kingdom stretches from one end of the universe to the other And they enunciate Your name . . . And this is the prayer: Blessed are You YHWH, the One God, Who created the universe with His One Name, Who formed all things with one utterance. High in the heavens did You establish Your Throne, You placed Your Chariot in the supernal firmament, You placed Your Inner Chamber in the heavenly vault, You planted [Your Sanctuary] among Ofannim of Glory. Legions of fire glorify Your Name, Seraphim of fire exult in Your praise: They are all infused by a still, small voice, They utter praise as they walk, They walk in awe, clothed in fear, Burdened with pride to extol the Creator of all things, Full of eyes on their rims. Their appearance is like that of lightning, Their countenance is pleasing, their mouth delicious, One over against the other they bear and speak, Bearing and speaking pure Hayyot, Holy, Holy, Holy. The ministering angels recite before You, The sun's orb shines from their faces, Their radiance shines like the radiance of the sky, Their wings outspread, their hands outstretched, As the sound of rushing water is the sound of their wings, Fiery torches extrude and emerge from the orbs of their eyes, With a sound of great tumult they utter song before You, Full of radiance, emitting brightness, their radiance shines. Beauteous as they go, rejoicing as they come, happy as they stand, Their light is pleasing before Your Throne of Glory, In awe they do Your will, Offering Your great, mighty and awe-inspiring Name. Grandeur and glory, enunciating the Name of Your Kingdom in joy and gladness, For there is none like You and none like your priests and none like your pious servants, And there is nothing like Your great Name for ever and ever to all eternity Raging at the sea and it dries up, gazing upon the earth and it heaves, Quickening the dead, reviving the dead from their dust. Great is Your Name for ever, Mighty is Your Name for ever, Holy is Your Name for ever, The One God YHWH is One. YHV
They would take permission from one another so that one would not precede [the others] and be guilty of [a sin punishable by] burning; rather, they all commenced simultaneously. This is the basis for what is said in the K'dushah d'Yotzeir Or: "all, as one, respond [and proclaim God's holiness...]"
(א) וקרא וכו׳. שרף קורא לחבירו לומר קדוש כאחד ולא יקדים האחד לחבירו ואמר. הקול יוצא מבין כולם כאחד כאילו הוא קול אחד:
A seraph calls to its fellow to say "kadosh" as one; and one does not precede its fellow in saying it. The voice goes forth from among all of them as one, as if it is one voice.

