Thy father’s sister - The instance of Amram and Jochebed Exodus 6:20 seems to show that marriage with an aunt was not considered wrong by the Israelites when they were in Egypt.
Related Commentaries of Leviticus 18:12
Leviticus 18:12
12 Thou shalt not uncover the nakedness of thy father's sister: she is thy father's near kinswoman.