1 Corinthians 5:8

8.Now, in the solemnity of this sacred feast we must abstain from leaven, as God commanded the fathers to abstain. But from what leaven? As the outward passover was to them a figure of the true passover, so its appendages were figures of the reality which we at this day possess. If, therefore, we would wish to feed on Christ’s flesh and blood, let us bring to this feast sincerity and truth Let these be our loaves of unleavened bread Away with allmalice and wickedness, for it is unlawful to mix up leaven with the passover In fine, he declares that we shall be members of Christ only when we shall have renounced malice and deceit. In the meantime we must carefully observe this passage, as showing that the ancient passover was not merely μνημοσυνον, (293) a memorial of a past benefit, but also a sacrament, representing Christ who was to come, from whom we have this privilege, that we pass from death to life. Otherwise, it would not hold good, that in Christ is the body of the legal shadows. (Colossians 2:17.) This passage will also be of service for setting aside the sacrilege of the Papal mass. For Paul does not teach that Christ is offered daily, but that the sacrifice having been offered up once for all, it remains that the spiritual feast be celebrated during our whole life.