Ash Wednesday, in the Western Church, the first day of Lent (q.v.), so called from the ceremonial use of ashes, as a symbol of penitence, in the service prescribed for the day. The custom, which is ultimately based on the penance of “sackcloth and ashes” spoken of by the prophets of the Old Testament, has been dropped in those of the reformed Churches which still observe the fast; but it is retained in the Roman Catholic Church, the day being known as dies cinerum (day of ashes) or dies cineris et cilicii (day of ash and sackcloth). The ashes, obtained by burning the palms or their substitutes used in the ceremonial of the previous Palm Sunday, are placed in a vessel on the altar before High Mass. The priest, vested in a violet cope, prays that God may send His angel to hallow the ash, that it become a remedium salubre for all penitents. After another prayer the ashes are thrice sprinkled with holy water and thrice censed. Then the priest invites those present to approach and, dipping his thumb in the ashes, marks them as they kneel with the sign of the cross on the forehead (or in the case of clerics on the place of tonsure), with the words: Memento, homo, quid pulvis es et in pulverem reverteris (Remember, man, that thou art dust and unto dust thou shall return). The celebrant himself either sprinkles the ash on his own head in silence, or receives it from the priest of highest dignity present.
This ceremony is derived from the custom of public penance in the early Church, when the sinner to be reconciled had to appear in the congregation clad in sackcloth and covered with ashes (cf. Tertullian, De Pudicitia, 13). At what date this use was extended to the whole congregation is not known. The phrase dies cinerum appears in the earliest extant copies of the Gregorian Sacramentary, and it is probable that the custom was already established by the 8th century. The Anglo-Saxon homilist Aelfric, in his Lives of the Saints (996 or 997), refers to it as in common use; but the earliest evidence of its authoritative prescription is a decree of the synod of Beneventum in 1091.
Of the reformed Churches the Anglican Church alone marks the day by any special service. This is known as the Commination service, its distinctive element being the solemn reading of “the general sentences of God’s cursing against sinners, gathered out of the seven and twentieth chapter of Deuteronomy, and other places of Scripture.” The lections for the day are the same as in the Roman Church (Joel ii. 12, &c., and Matt. vi. 16, &c.). In the American Prayer Book the office of Commination is omitted, with the exception of the three concluding prayers, which are derived from the prayers and anthems said or sung during the blessing and distribution of the ashes according to the Sarum Missal. The ceremonial of the ashes was not proscribed in England at the Reformation; it was indeed enjoined by a proclamation of Henry VIII. (February 26, 1538) and again in 1550 under Edward VI.; but it had fallen into complete disuse by the beginning of the 17th century.
See Wetzer and Welte, Kirchenlexikon, and Herzog-Hauck, Realencyklopädie (3rd ed.), s. “Aschermittuoch”; L. Duchesne, Christian Worship, trans. by M.L. McClure (London, 1904).