Hebrews 5:1

Every high priest. He speaks first of the office of priests in general, before he speaks of Christ's priesthood. A priest is chosen and preferred before other men, as qualified for the divine ministry, to offer up gifts, oblations, sacrifices, in order to obtain forgiveness for his own sins and those of the people, who, by the experience he has of his own infirmities, may compassionate others who offend through frailty or ignorance, every priest (excepting our Saviour Christ) being a sinner. Nor must he take upon himself rashly and inconsiderately, for temporal motives, this sacred ministry, formidable (says St. Gregory) even for the shoulders of Angels; he must consult God by prayer, follow the advice of his spiritual guides and pious parents; by these means to know whether he has a call from God to this ministry, as Aaron had. (Witham) --- The priest and pastor should never forget that he is a man and a sinner; that he is honoured with this divine ministry, to offer sacrifice both for his own sins and for the sins of the faithful; that prayer should be his delight, the altar his centre, and the sacrifice of the body and blood of Christ his supreme felicity. "This sacrifice of the Eucharist," says St. Augustine, "has succeeded to all the ancient victims that were immolated of old, to signify the future sacrifice." (lib. 10. chap. xx. de Civit. Dei.) As to the word mass, it was in use to signify this holy sacrifice of the altar above thirteen hundred years ago. See the second Council of Carthage, canon 3.; St. Jerome upon the Prov. chap. xi.; St. Ambrose, lib. 2. ep. 14. Missa facere c\'9cpi; I began to say mass. It was introduced into this country [Great Britain] with Christianity itself. See Ven. Bede's history, chap. xxvii. & b. 4. chap. xiv.