Commentaire sur Ézéchiel 1:7

were straight legs [Jonathan renders]: רִגְלִין כֵּיוָנָן parallel legs, this one opposite this one. Another explanation: “straight,” meaning they had no knee joints by which to bend their legs because they do no sitting or lying. Therefore they do not require joints like those of animalsthe upper joint and the lower joint by which it bends its legs to lie down.

a round foot Heb. עֵגֶל, a round foot, and so did Jonathan render it: round feet.

and they sparkled Because of their brilliance, sparks seemed to emanate from them, as we say in tractate Yoma (37b): She too [Queen Helene] made a golden candelabrum, etc. When the sun shone, sparks would [seemingly] emanate from it, etc. וְנוֹצְצִים is etincelants in French, gleaming.

like the color Heb. כְּעֵין, like מַרְאֶה, the appearance.

burnished copper Heb. קָלָל, clarified and gleaming. Menachem (Machbereth p. 155) associated it with (Lev. 2: 14): “roasted (קָלוּי) in fire.”