וְרַגְלֵיהֶ֖ם רֶ֣גֶל יְשָׁרָ֑ה וְכַ֣ף רַגְלֵיהֶ֗ם כְּכַף֙ רֶ֣גֶל עֵ֔גֶל וְנֹ֣צְצִ֔ים כְּעֵ֖ין נְחֹ֥שֶׁת קָלָֽל׃
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 the colour of burnished brass.
Read kabbalistic (mystical) interpretation of Ezekiel 1:7: and classical mystical sources.