מַרְאֵ֨ה הָאוֹפַנִּ֤ים וּמַעֲשֵׂיהֶם֙ כְּעֵ֣ין תַּרְשִׁ֔ישׁ וּדְמ֥וּת אֶחָ֖ד לְאַרְבַּעְתָּ֑ן וּמַרְאֵיהֶם֙ וּמַ֣עֲשֵׂיהֶ֔ם כַּאֲשֶׁ֛ר יִהְיֶ֥ה הָאוֹפַ֖ן בְּת֥וֹךְ הָאוֹפָֽן׃
The appearance of the wheels and their work was like unto the colour of a beryl; and they four had one likeness; and their appearance and their work was as it were a wheel within a wheel.
Read halakhic rulings (Jewish law) on Ezekiel 1:16: and classical halakhic sources.