“Then Pharaoh gave Joseph a new Egyptian name, Zaphenath-paneah. He also gave him a wife, whose name was Asenath. She was the daughter of Potiphera, the priest of On. So Joseph took charge of the entire land of Egypt” (Genesis 41:45 NLT).

When Pharaoh promoted Joseph to be his second-in-command, he also gave him a new name, “Zaphenath-paneah” (“God speaks and lives”), and a new wife, “Asenath” (“Gift of the Sun-god”). The Egyptian king wanted Joseph to have an Egyptian name and an Egyptian wife from an influential Egyptian family, the priestly family of Potiphera, “priest of On” (“On,” also known as Heliopolis, “The City of the Sun,” was the center of worship of the sun-god, Ra, located 10 miles northeast of modern Cairo.). This new title, name, wife, and family were given to him by Pharaoh. But really… weren’t they actually given to him by God?
For it was God’s purpose to put Joseph in power in Egypt to preserve Israel and to show His great power and glory 400 years later when He brought them out with a strong hand. Two sons, Manasseh and Ephraim, were born to Joseph and Asenath. They became equal with the 12 sons of Israel when Jacob blessed them as his own sons (Gen. 48:5). Therefore, when God chose the tribe of Levi to be His own possession, the addition of Manasseh and Ephraim maintained the number of Israel’s tribes at twelve.
No, Joseph didn’t sin. He lived before the Mosaic law and the New Testament warning (2 Cor. 6:14). Joseph was obedient to God’s purpose for his life, of which he had dreamed when he was a boy.