Philo Judaeus De Migratione Abrahami 162

[162] But you may learn to perceive how wavering a disposition such a man has from the oaths which he swears, swearing at one time "by the health of Pharaoh," ¹ and then again, on the contrary, "not by the health of Pharaoh." But this latter formula of oath, which contains a negation, looks as if it were the injunction of his father’s house, which is always meditating the destruction of the passions, and wishing that they should die; but the other brings us back to the discipline of Egypt, which desires that these passions should be preserved;