A group of people went to Imam Shafe’i demanding proof for the existence of Allah (the Exalted). He considered it for a moment and then replied that the proof is the leaf of the mulberry bush. This was puzzling to all. How can this particular leaf be a proof of Allah’s existence? Imam Shafe’i replied that the taste of the substance of this bush is one; however, when a silkworm eats its leaf, it comes out of the worm as silk, yet when a bee does the same, what is produced is honey. Likewise, when a deer consumes it, what is produced is musk. He continued to explain that one should ponder upon the Creator of such a phenomenon- Who allows a variety of results to be derived from a single source.
Gems & Jewels p.71