एतयोर्यदुपादानमेकं सूक्ष्मं सदव्ययम् ।यथैव मृद्घटादीनां विचारः सोऽयमीदृशः ॥ १५ ॥
In plain words
What is the one material these two are made of — subtle, real, never wearing away — the way clay is what the pot and everything like it is made of? This is the inquiry. This is what it looks like.
Close to the Sanskrit
That which is the material cause of these two — one, subtle, existent, imperishable — just as clay is of pots and the rest: this inquiry is of such a kind.