Maat, also known as Ma'at, is the Egyptian goddess of truth, justice, wisdom, the stars, law, morality, order, harmony, the seasons, and cosmic balance. She is the daughter of Ra and Hathor, and is the consort of Thoth, with whom she had a daughter, Seshat, who is the goddess of wisdom, knowledge, and writing.
She holds a major in role in Duat, the Egyptian underworld, where she providees Anubis and Osiris a feather, which is used to weigh the heart/soul of everyone who dies. If the heart is lighter than the feather, the deceased gets to join Osiris in the afterlife, if not, they either cease to exist or are thrown to into a Lake of Fire.