The affix kha comes in the sense of 'what bears it' after the word sarvadhurā being in Accusative -2nd case construction.,
Thus सर्वधुरां वहति = सर्वधुरीणः 7.1.2. The affix ख applies to other compounds also ending in धुर, e.g. उत्तरधुरीणः, दक्षिनधुरीणः ॥ The word सर्वधुर is a compound of सर्वा + धुर् 2.1.49, the samasanta अ being added by 5.4.74. The word धूः being feminine, the whole compound would be feminine by 2.4.26. The word सर्वधुरात् in the sutra should not be taken, therefore, as regulating the gender, for though it is in the masculine gender, the affix comes after the feminine word. In fact सर्वधुर in the sutra should be taken as a nominal-stem or pratipadika equal to सवधुरा ॥,