Verse 20

इदं रुक्ममिदं भस्म परिज्ञातमिति स्फुटम् ।न यथा हेमकारस्य हेमज्ञानात्मनस्तथा

In plain words

'This is gold, this is ash' -- that is plainly known; but not as it is for the goldsmith, whose very being is the knowledge of gold.