A little ancient ethnic stereotyping:
Nowadays no criminal sneaks up to you Egyptian style as you’re walking along and does you a mischief like the tricks those deceitful scoundrels used to play, nasty rascals all as bad as each other, curse the lot of them. – Theocritus, Idyll 15.45
Egyptians were hated by much of Greco-Roman culture. The burden of lots of Josephus' work is to prove that the Israelites come out of Egypt but were not native Egyptians (as some Greek historians had it).