Gregory the Great

But ask now the beasts, and they shall teach thee; and the fowls of the air, and they shall tell thee. Or speak to the earth, and it shall answer thee: and the fishes of the sea shall declare unto thee.

What are we to understand by 'the beasts,' but men of slow parts; and what by 'the fowls of the air,' but those that are skilled in high and sublime truths? For of 'the beasts,' i.e. the dull of sense, it is written; Thine animals shall dwell therein. And forasmuch as those, who have minds for sublime themes, soar among the words of the Redeemer, it is written, So that the birds of the air come and lodge in the branches thereof. And what by 'the earth,' saving men whose taste is for earthly things? Hence too it is said to the first man on his forsaking the things of heaven, Dust thou art, and unto dust shalt thou return. What are we to understand by 'the fishes of the sea,' but the inquisitive ones of this world, concerning whom the Psalmist saith, The fish of the sea, that pass through the paths of the seas. Which same busy themselves in large researches into things, as it were in undiscoverable floods.