I Kings 6:33 Halakhah

וְכֵ֥ן עָשָׂ֛ה לְפֶ֥תַח הַֽהֵיכָ֖ל מְזוּז֣וֹת עֲצֵי־שָׁ֑מֶן מֵאֵ֖ת רְבִעִֽית׃

So also made he for the entrance of the temple door-posts of olive-wood, within a frame four-square;