The affix kha comes in the sense of a descendant after the prātipadika (Nominal Stem) kula and a compound word that ends in kula,
In the next sutra, it will be taught that the word कुल when not preceded by any other word, takes the affixes 'yat' and 'dhakan.' That indicates by implication that the present sutra applies to the simple word कुल and to the words ending in कुल also. Thus कुलीनः, आढ्यकुलीनः, श्रोत्रियकुलीनः ॥,