A metaphor:

The glory of God no man or angel shall know, preached Thomas Shepard; "their cockle shell can never comprehend this sea"; we can only apprehend Him by knowing that we cannot comprehend Him at all, "as we admire the luster of the sun the more in that it is so great we can not behold it." (in Perry Miller's essay "The Marrow of Puritan Divinity")

"their cockle shell can never comprehend this sea" — I like that.

Around the same time, Andrew Marvell's father wrote, in a request for funds for a school library, "Scholers are like other tradesmen, they cannot worke w'thout tooles, nor, spider like, weave their web out of their own bellyes." (quoted in Nicholas Murray's biography of Marvell)