https://www.ou.org/holidays/the_thirty_nine_categories_of_sabbath_work_prohibite...

		kragen 15 days ago \| parent \| context \| favorite \| on: School cell phone bans and student achievement https://www.ou.org/holidays/the_thirty_nine_categories_of_sa... outlines those "clear boundaries" in detail from a pre-medieval or early medieval perspective.