John 13:10

He that is washed, &c. The feet are always apt to contract some dust or dirt; and in the mystical sense, he that is washed by the sacraments of baptism, or penance, from greater sins, must still endeavour to cleanse, and purify his affections from lesser failings of human frailty. And you, my apostles, are clean from greater offences, but not all of you, meaning the traitor Judas. (Witham) --- It is impossible that the extremities of the soul (if we may be allowed the expression) should not, as long as we tread upon this earth, receive some stain or other; although in the opinion of men, the soul appear just. Many indeed after baptism, are covered with the dust of sin, even to the head, but those who are disciples indeed, need only to wash their feet. (Origen, tract. 32. in Joan.) --- The foulness of the feet, when the rest is clean, signifies the earthly affections, and remains of former sins remitted, which are to be cleansed by devout acts of charity and humility. (St. Ambrose, lib. iii. de Sacram. chap. 1; St. Bernard, de cæn. Dom. ser. 1.) --- Though his disciples were clean, still he washed their feet, comformably to that of the Apocalypse, chap. xxii. "He that is clean, let him be cleansed still." (Origen, tract. 32. in Joan.)