Ash Wednesday

Ash Wednesday is the first day of the Lenten season. On this day all the faithful, according to ancient custom, approach the altar before the priest, dipping his thumb into ashes previously blessed and marks the forehead with the sign of the cross, saying the words: "Remember man that thou art dust and unto dust thou shalt return." The ashes used in this ceremony are made by burning the remains of the palms blessed on the Palm Sunday of the previous year.
In the blessing of the ashes four prayers are used, all of them ancient. The ashes are sprinkled with holy water and fumigated with incense.

There can be no doubt that the custom of distributing the ashes to all the faithful arose from a devotional imitation of the practice observed in the case of public penitents. But this devotional usage, the reception of a sacramental which is full of the symbolism of penance

In the books both in the Old Law and in the New that the men who repented of their sins bestrewed themselves with ashes and clothed their bodies with sackcloth. Now let us do this to signify that we ought to repent of our sins during the Lenten season.