Slavery in ancient Israel. Difference between Hebrew slaves and Canaanite slaves. Seal of slavery was not be worn on Shabbos for several reasons, including that it might become detached and the slave would come to carry it in the public domain. Difference between metal seals and clay seals. Same rule applied to Sages associated with the House of the Exilarch in Babylonia. Same for bells, unless woven into garment.