The affix kvipcomes after the verb su 'to press out juice' with the sense of past time, when the word soma , in the Accusative -2nd case, is in composition.,
As, सोमसुत् 'who has pressed the soma juice, or soma-distiller'; 1st. dual सोमसुतौ; 1st. plural सोमसुतः ।
This sutra is also for the sake of making a niyama or restrictive rule. The four-fold restriction is here intended. i. e. as regards the verb, the tense, the upapada and the affix.,