N orth ▁Arab ians "; ▁Arab ▁tradition ▁traces ▁the ▁descent ▁of ▁all ▁Arab ▁tribes ▁to ▁either ▁Ad nan ▁or ▁Q a ht an , ▁father ▁of ▁the ▁" S outh ▁Arab ians ". ▁By ▁the ▁dawn ▁of ▁Islam ▁in ▁the ▁mid - 7 th ▁century , ▁the ▁descend ants ▁of ▁Q ays ▁were ▁so ▁numerous ▁and ▁so ▁significant ▁a ▁group ▁that ▁the ▁term ▁Q ays ī ▁came ▁to ▁refer ▁all ▁North ▁Arab ians . ▁ ▁Branch es ▁The ▁Q ays ▁consisted ▁of ▁several ▁branches , ▁which ▁were ▁divided ▁into ▁further ▁sub - t rib es . ▁The ▁first - t ier ▁divisions , ▁i . e . ▁the ▁sons ▁of ▁Q ays ▁' A yl an , ▁were ▁K has af a , ▁Sa ' d ▁and ▁' Am r . ▁ ▁K has af a ▁ ▁From ▁K has af a ▁desc ended ▁the ▁large ▁tribes ▁of ▁Haw az in ▁and ▁Ban u ▁Sul ay m , ▁both ▁of ▁whose ▁found ers ▁were ▁sons ▁of ▁Mans ur ▁ibn ▁I kr ima ▁ibn ▁K has af a , ▁and ▁the ▁Ban u ▁Mu har ib , ▁whose ▁founder ▁was ▁the ▁son ▁of ▁Z iy ad ▁ibn ▁K has af a . ▁The ▁Haw az in ▁was ▁a ▁large ▁trib al ▁grouping ▁that ▁included ▁several ▁large ▁sub - t rib es . ▁Among ▁them ▁were ▁the ▁Ban u ▁' Am ir , ▁whose ▁pro gen itor ▁was ▁' Am ir ▁ibn ▁Sa ' sa ' ▁ibn ▁Mu ' aw i ya ▁ibn ▁Bak r