“Egypt is magic” is a cultural assumption that dates back millennia. In part, it was a narrative which the ancient Egyptians promoted about themselves; magicians were a part of their culture, and their civilisation was ancient enough that over time understanding of its earlier phases passed into legend and myth as much as official history. (More time passed between the Great Pyramid’s construction and the dawning of Christianity than have passed between now and the Crucifixion, after all.)
It was also a bit of PR which numerous other Mediterranean cultures bought into, and became a recurring assumption in European culture as a whole. The Greeks bought into it, the Romans bought into it, Jewish sources like Exodus and the Talmud bought into it, and so it’s no surprise that much of Christendom bought into it, Enlightenment-era Freemasons and other such esoteric societies bought into it – particularly after Napoleon’s invasion of Egypt rekinded a general interest in Egyptology, the Golden Dawn bought into it to the extent that most of their rituals involved extensive riffs on Egyptian myth, and Crowley bought into it so hard that his Book of the Law was steeped in Egyptian imagery and received during a honeymoon in Cairo.
Many occult practitioners like to hype up the extent to which they are participating in a tradition which winds its way back through the ages to ancient Egypt. The extent to which is the case has always been doubtful. The myth that the tarot dates back to Egyptian times seems to have little to no basis in fact, and the Golden Dawn’s rituals reflect tentative Victorian reconstructions of Egyptian religion more than they do actual practices handed down through the years by a centuries-old tradition.
However, whilst there is little evidence for a tradition passed down on an institutional or personal level – no secret society or Sith-style chain of master and apprentice winding its way back through the years to connect modern occult groups to the practitioners of ancient Egypt, there is evidence for a literary or textual tradition being passed down – concepts in Egyptian writing on the subject of magic which ended up in some fashion influencing the medieval grimoires which Renaissance and Enlightenment-era magicians would then develop in their own directions and make their own additions to.
Perhaps the most extensive collection of material we have on Egyptian magical practices are what’s known as the Greek Magical Papyri, a collection of magical texts – including what seem to be the handbooks used by actual practicing magicians – that had been accumulated in private collections in the post-Napoleon burst of Egyptological research.