▁well ▁as ▁the ▁boot y ▁which ▁could ▁be ▁used ▁to ▁supp lement ▁future ▁campaign s . ▁ ▁The ▁Jews ▁of ▁Kh ay bar ▁finally ▁surrender ed ▁after ▁seeing ▁no ▁way ▁out ▁and ▁were ▁allowed ▁to ▁live ▁in ▁the ▁o asis ▁on ▁the ▁condition ▁that ▁they ▁would ▁give ▁one - half ▁of ▁their ▁produce ▁to ▁the ▁Muslim s . ▁Jews ▁continued ▁to ▁live ▁in ▁the ▁o asis ▁for ▁several ▁more ▁years ▁until ▁they ▁were ▁exp elled ▁by ▁cal i ph ▁U mar . ▁The ▁im position ▁of ▁t ribute ▁upon ▁the ▁conquer ed ▁Jews ▁served ▁as ▁a ▁preced ent ▁for ▁prov isions ▁in ▁the ▁Islam ic ▁law ▁requiring ▁the ▁ex action ▁of ▁t ribute ▁known ▁as ▁j iz ya ▁from ▁D him mi ▁subjects ▁in ▁areas ▁under ▁Muslim ▁rule , ▁and ▁conf is cation ▁of ▁land ▁belonging ▁to ▁non - Mus lim s ▁into ▁the ▁collect ive ▁property ▁of ▁the ▁Muslim ▁community . ▁ ▁Background ▁ ▁Kh ay bar ▁in ▁the ▁ 7 th ▁century ▁ ▁In ▁the ▁sevent h ▁century , ▁Kh ay bar ▁was ▁inhab ited ▁by ▁Jews . ▁The ▁inhabitants ▁had ▁stored ▁in ▁a ▁red ou bt ▁at ▁Kh ay bar ▁a ▁sie ge - engine , ▁s words , ▁l ances , ▁shield s ▁and ▁other ▁weapon ry . ▁In ▁the ▁past ▁some ▁sch ol ars ▁attempted ▁to ▁explain ▁the ▁presence ▁of ▁the ▁weapons , ▁suggesting ▁that ▁they ▁were ▁used ▁for ▁sett ling ▁quar rel s ▁among ▁the ▁families ▁of ▁the ▁community . ▁V ag lier i ▁suggests ▁that ▁it