Ma'at is symbolized with the "feather of truth, balancing scales, her All-Seeing Eye, her throne, the gates to the underworld and her faithful guardian, the dog". (Andrews, Munya, The Seven Sisters of the Pleiades). In balancing the scales, Anubis would place the subjects heart on one side, with the other side containing Ma'at's feather. One interpretation as pointed out by Munya Andrews is that "[t]o be light as a feather meant one was unburdened by sin and therefore exonerated in death". (Id, citing to Walker, Womens Dictionary of Symbols and Sacred Objects.)
The concept of Judgment in both its exoteric and esoteric meaning as found in modern culture come from Egypt. The scales and sword of Lady Justice are a derivative of Ma'at's scales and feather of Truth. As recorded by the scribe Thoth and assessed by the ruler of the afterlife Anubis, Ma'at's scales adjudicate whether an individual has followed the Truth of her own Heart. That is your Judgment Day.
Overly educated and continuously exploring and revealing more behind the veil.
"It cannot be too highly emphasized that the mystic swims in the same waters in which the psychotic drowns."
-James Wasserman, The Mystery Traditions