Charles Ellicott Commentary Ezekiel 1:7

"And their feet were straight feet; and the sole of their feet was like the sole of a calf`s foot; and they sparkled like burnished brass." — Ezekiel 1:7 (ASV)

Their feet were straight feet. —Rather, each of their legs was a straight leg, that is, without any bend in it, as at the knee, but was equally fitted for motion in any direction. So also the sole of their feet, the part which rested on the ground, was not, like the human foot, formed to move forward only, but was round and solid, something like the sole of a calf’s foot.

They sparkled. —This refers only to the sole of the feet, the hoof. The burnished brass is a different word from that used in Ezekiel 1:4, and gives another feature to the general brilliancy and magnificence of the vision.