Since, however, the reason for the precept, “Thou shalt not go up by steps unto My altar” (Ex. 20:26) is stated to have been “lest thy nakedness be discovered,” it should be observed that this too was instituted with the purpose of preventing idolatry, for in the feasts of Priapus the Gentiles uncovered their nakedness before the people.  But later on the priests were prescribed the use of loin-cloths for the sake of decency:  so that without any danger the altar could be placed so high that the priests when offering sacrifices would go up by steps of wood, not fixed but movable.

Reply Obj. 8:  The body of the tabernacle consisted of boards placed on end, and covered on the inside with curtains of four different colors, viz. twisted linen, violet, purple, and scarlet twice dyed.  These curtains, however, covered the sides only of the tabernacle; and the roof of the tabernacle was covered with violet-colored skins; and over this there was another covering of rams’ skins dyed red; and over this there was a third curtain made of goats’ hair, which covered not only the roof of the tabernacle, but also reached to the ground and covered the boards of the tabernacle on the outside.  The literal reason of these coverings taken altogether was the adornment and protection of the tabernacle, that it might be an object of respect.  Taken singly, according to some, the curtains denoted the starry heaven, which is adorned with various stars; the curtain (of goats’ skin) signified the waters which are above the firmament; the skins dyed red denoted the empyrean heaven, where the angels are; the violet skins, the heaven of the Blessed Trinity.

The figurative meaning of these things is that the boards of which the tabernacle was constructed signify the faithful of Christ, who compose the Church.  The boards were covered on the inner side by curtains of four colors:  because the faithful are inwardly adorned with the four virtues:  for “the twisted linen,” as the gloss observes, “signifies the flesh refulgent with purity; violet signifies the mind desirous of heavenly things; purple denotes the flesh subject to passions; the twice dyed scarlet betokens the mind in the midst of the passions enlightened by the love of God and our neighbor.”  The coverings of the building designate prelates and doctors, who ought to be conspicuous for their heavenly manner of life, signified by the violet colored skins:  and who should also be ready to suffer martyrdom, denoted by the skins dyed red; and austere of life and patient in adversity, betokened by the curtains of goats’ hair, which were exposed to wind and rain, as the gloss observes.

Reply Obj. 9:  The literal reason for the sanctification of the tabernacle and vessels was that they might be treated with greater reverence, being deputed, as it were, to the divine worship by this consecration.  The figurative reason is that this sanctification signified the sanctification of the living tabernacle, i.e. the faithful of whom the Church of Christ is composed.