What is the origin of bezoar?

Bezoar “a calculus found in the stomach of ruminants, formerly reputed to be an effective remedy for poison” is derived via Medieval Latin bezahar and Arabic bāzahr from Persian pād-zahr “antidote.” This Persian term is a compound of the elements pād- “protector” and zahr “poison.” Pād- comes from the Proto-Indo-European root pā- “to protect, feed,” which is also the source of food, fodder, and foster (via Old English); forage and fur (via Old French and Germanic); and recent Word of the Day selection repast (via Latin). Zahr also comes from a Proto-Indo-European root, gwhen- “to strike, kill,” which is the source of bane (from Old English bana “slayer”), defend and offend (from Latin dēfendere “to repel, ward off” and offendere “to strike against”), and gun (from Old Norse gunnr “war”). Bezoar was first recorded in English in the 1470s.