▁and ▁in ▁need ▁of ▁resources , ▁the ▁lack ▁of ▁central ▁authority ▁at ▁Kh ay bar ▁prevent ed ▁any ▁un ified ▁def ensive ▁prepar ations , ▁and ▁quar rel s ▁between ▁different ▁families ▁left ▁the ▁Jews ▁dis organ ized . ▁The ▁Ban u ▁F az ara , ▁related ▁to ▁the ▁Gh ata fan , ▁also ▁offered ▁their ▁assistance ▁to ▁Kh ay bar , ▁after ▁their ▁un success ful ▁negoti ations ▁with ▁the ▁Muslim s . ▁ ▁Fail ure ▁of ▁Ban u ▁Gh ata fan ▁ ▁During ▁the ▁battle , ▁the ▁Muslim s ▁were ▁able ▁to ▁prevent ▁Kh ay bar ' s ▁Gh ata fan ▁al lies ▁( cons isting ▁of ▁ 4 , 0 0 0 ▁men ) ▁from ▁providing ▁them ▁with ▁rein for c ements . ▁One ▁reason ▁given ▁is ▁that ▁the ▁Muslim s ▁were ▁able ▁to ▁buy ▁off ▁the ▁Bed ou in ▁al lies ▁of ▁the ▁Jews . ▁W att , ▁however , ▁suggests ▁that ▁rum ors ▁of ▁a ▁Muslim ▁attack ▁on ▁Gh ata fan ▁strong holds ▁might ▁also ▁have ▁played ▁a ▁role . ▁According ▁to ▁Tab ari , ▁Muhammad ' s ▁first ▁stop ▁in ▁his ▁con quest ▁of ▁Kh ay bar ▁was ▁in ▁the ▁valley ▁of ▁al - R aj i , ▁which ▁was ▁directly ▁between ▁the ▁Gh ata fan ▁people ▁and ▁the ▁Kh ay bar . ▁In ▁hearing ▁the ▁news ▁of ▁the ▁Muslim ▁army ' s ▁position , ▁the ▁Gh ata fan ▁organized ▁and ▁rode ▁out ▁to ▁honor ▁their ▁al liance ▁with ▁the ▁Kh ay bar . ▁After ▁a ▁day