Matthew 4:2

KJV
[2] And when he had fasted forty days and forty nights, he was afterward an hungred.

I believe this is kind of a template for the hermit, not that this necessarily came first. In fact, I think the hermit happened first, whether it started with Judaism or another North African religion, I don't know. I don't think anybody knows. But this meme started around 0AD of people going into the desert to get wisdom from isolation, or to seek God or gods that way.

BTW, do NOT try this at home. Forty days without food is death, and not a pleasant one.