Madhvaon Brahma Sūtra 1.4.2

By the word Avyakta ‘ not manifest ’ is expressed only what is subtle. For only that which is subtle may (naturally) be not manifest. ’The Brahman being most subtle in its character, is rightly spoken of (as not manifest) and the (absolute) subtlety is per- fectly true of Him alone. It is said in the Pippa- lada Sakha, “ That most subtle thing which ought to be known is the eternal nature of Vishnu, the wise say, “ that which the multitude does not understand and which is the most exalted above all things of the world, the wise who are deep in meditation find.” And while the thing which the word primarily denotes is presented, it is not justifiable to take that which is denoted (by the word) in the secondary sense.