Today is "...the seventh Wednesday before Easter Sunday...the first day of the Season of Lent. Its name comes from the ancient practice of placing ashes on worshippers’ heads or foreheads as a sign of humility before God, a symbol of mourning and sorrow at the death that sin brings into the world. It not only prefigures the mourning at the death of Jesus, but also places the worshipper in a position to realize the consequences of sin. (See Reflections on Ash Wednesday). Ash Wednesday is a somber day of reflection on what needs to change in our lives if we are to be fully Christian. "
"In the early church, ashes were not offered to everyone but were only used to mark the forehead of worshippers who had made public confession of sin and sought to be restored to the fellowship of the community at the Easter celebration. However, over the years others began to show their humility and identification with the penitents by asking that they, too, be marked as sinners. Finally, the imposition of ashes was extended to the whole congregation in services similar to those that are now observed in many Christian churches on Ash Wednesday. Ashes became symbolic of that attitude of penitence reflected in the Lord’s prayer: “forgive us our sins, for we ourselves forgive everyone indebted to us” (Luke 11:4, NRSV)."
*Once again, thanks to Dennis Bratcher, the same source I turned to at Advent.