The figurative reason for these feasts was that the continual sacrifice of the lamb foreshadowed the perpetuity of Christ, Who is the “Lamb of God,” according to Heb. 13:8:  “Jesus Christ yesterday and today, and the same for ever.”  The Sabbath signified the spiritual rest bestowed by Christ, as stated in Heb. 4.  The Neomenia, which is the beginning of the new moon, signified the enlightening of the primitive Church by Christ’s preaching and miracles.  The feast of Pentecost signified the Descent of the Holy Ghost on the apostles.  The feast of Trumpets signified the preaching of the apostles.  The feast of Expiation signified the cleansing of the Christian people from sins:  and the feast of Tabernacles signified their pilgrimage in this world, wherein they walk by advancing in virtue.  The feast of Assembly or Congregation foreshadowed the assembly of the faithful in the kingdom of heaven:  wherefore this feast is described as “most holy” (Lev. 23:36).  These three feasts followed immediately on one another, because those who expiate their vices should advance in virtue, until they come to see God, as stated in Ps. 83:8. ________________________

FIFTH ARTICLE [I-II, Q. 102, Art. 5]

Whether There Can Be Any Suitable Cause for the Sacraments of the Old
Law?

Objection 1:  It would seem that there can be no suitable cause for the sacraments of the Old Law.  Because those things that are done for the purpose of divine worship should not be like the observances of idolaters:  since it is written (Deut. 12:31):  “Thou shalt not do in like manner to the Lord thy God:  for they have done to their gods all the abominations which the Lord abhorreth.”  Now worshippers of idols used to knive themselves to the shedding of blood:  for it is related (3 Kings 18:28) that they “cut themselves after their manner with knives and lancets, till they were all covered with blood.”  For this reason the Lord commanded (Deut. 14:1):  “You shall not cut yourselves nor make any baldness for the dead.”  Therefore it was unfitting for circumcision to be prescribed by the Law (Lev. 12:3).

Obj. 2:  Further, those things which are done for the worship of God should be marked with decorum and gravity; according to Ps. 34:18:  “I will praise Thee in a grave [Douay:  ‘strong’] people.”  But it seems to savor of levity for a man to eat with haste.  Therefore it was unfittingly commanded (Ex. 12:11) that they should eat the Paschal lamb “in haste.”  Other things too relative to the eating of the lamb were prescribed, which seem altogether unreasonable.

Obj. 3:  Further, the sacraments of the Old Law were figures of the sacraments of the New Law.  Now the Paschal lamb signified the sacrament of the Eucharist, according to 1 Cor. 5:7:  “Christ our Pasch is sacrificed.”  Therefore there should also have been some sacraments of the Old Law to foreshadow the other sacraments of the New Law, such as Confirmation, Extreme Unction, and Matrimony, and so forth.