Maat was the Egyptian goddess of cosmic order and truth. She was a minor deity recognized from the middle of the third millennium, perhaps earlier, closely associated with the creator deities, and particularly the sun god.
Later she was described as the “daughter of Re.” Her only known sancturary was the complex of Karnak at Thebes. She was depicted either in human form wearing an ostrich plume on her head or by an ostrich feather alone.
The rulers of Egypt believed that they governed under Maat’s aegis and were frequently described, by order, as the “beloved of Maat”.
Also Maat was believed to be integral to the success of the soul passing through the Hall of the Two Truths, where the heart was weighed, to reach paradise, because as the personification of truth and justice her feather was placed in one pan of the scale used for weighing the heart. (see Book of the Dead)
Jordan, Michael, Encyclopedia of Gods, New York, Facts On File, Inc. 1993, p. 150
Cotterell, Arthur, A Dictionary of World Mythology, New York, G. P. Putman’s Sons, 1980, p. 38