Who wrote the rhyme how large unto tiny fly?

The rhyme "How large unto tiny fly" is from the poem "The Fly" by William Blake.

Here's the full stanza:

"How large unto tiny fly

Must little fly appear!

Whose size is so exceedingly small

He cannot see the little fly

And feels a dreadful pain

Because he cannot see the little fly

And thinks his life in vain."

This poem explores the perspective of a fly and the fear it experiences due to its own size.