Why would anybody? :^)
[Egyptians] are the only people in the world -- they at least, and such as have learnt the practice from them -- who use circumcision... They practise circumcision for the sake of cleanliness, considering it better to be cleanly than comely... the Colchians, the Egyptians, and the Ethiopians, are the only nations who have practised circumcision from the earliest times. The Phoenicians and the Syrians of Palestine themselves confess that they learnt the custom of the Egyptians; and the Syrians who dwell about the rivers Thermodon and Parthenius, as well as their neighbours the Macronians, say that they have recently adopted it from the Colchians. Now these are the only nations who use circumcision, and it is plain that they all imitate herein the Egyptians. With respect to the Ethiopians, indeed, I cannot decide whether they learnt the practice of the Egyptians, or the Egyptians of them...
Histories, book II: Euterpe by Herodotus, translation by George Rawlinson, transcription by Daniel C. Stevenson
It’s interesting that the only gentiles allowed to marry Israelites were Egyptians........