It's a modern myth that dates to the 1800's. It's not older than that -- there were no wolves in Egypt, so nothing that they wrote would have to do with wolves. Nor are there myths where Horus cried.

This appears to refer to Albert Pike's Masonic writings (and the Masons made things up... completely...) On page 6, for instance, he completely misidentifies the Egyptian hieroglyph as a "bridge" and much later says the "Egyptians and Persians" "sacrificed to water."

It's full of imaginary and made-up things like that.

[books.google.com]