Jamieson, Fausset and Brown on Isaiah 19:11

11. Zoan--The Greeks called it Tanis, a city of Lower Egypt, east of the Tanitic arms of the Nile, now San; it was one the Egyptian towns nearest to Palestine (Nu 13:22), the scene of Moses' miracles (Psa 78:12, 43). It, or else Memphis, was the capital under Sethos.

I am ... son of the wise ... kings--Ye have no advice to suggest to Pharaoh in the crisis, notwithstanding that ye boast of descent from wise and royal ancestors. The priests were the usual "counsellors" of the Egyptian king. He was generally chosen from the priestly caste, or, if from the warrior caste, he was admitted into the sacred order, and was called a priest. The priests are, therefore, meant by the expression, "son of the wise, and of ancient kings"; this was their favorite boast (Herodotus, 2.141; compare Am 7:14; Ac 23:6; Php 3:5). "Pharaoh" was the common name of all the kings: Sethos, probably, is here meant.