Ash Wednesday, the first day of Lent, so called from a custom in the Western Church of sprinkling ashes on the heads of penitents admitted to penance that day. The custom is said to have originated with Gregory the Great. In the Roman Catholic Church the ashes are consecrated on the altar, sprinkled with holy water and then cast on the heads of the clergy and people, the priest saying in Latin, "Remember that thou art dust and to dust thou shalt return."