Calvin and Lent

ST. PAUL hath shown us that we must be ruled by the Word of God, and hold the commandments of men as vain and foolish; for holiness and perfection of life belongeth not to them. He condemneth some of their commandments, as when they forbid certain meats, and will not suffer us to use that liberty which God giveth the faithful. Those who troubled the church in St. Paul’s time, by setting forth such traditions, used the commandments of the law as a shield. These were but men’s inventions: because the temple was to be abolished at the coming of our Lord Jesus Christ. Those in the church of Christ, who hold this superstition, to have certain meats forbidden, have not the authority of God, for it was against His mind and purpose that the Christian should be subject to such ceremonies.

Then he goes on to say this:

Shall it then be lawful to observe what men have framed in their own wisdom? Do we not see that it is a matter which goeth directly against God? St. Paul setteth himself against such deceivers: against such as would bind Christians to abstain from meats as God had commanded in His law. If a man say, it is but a small matter to abstain from flesh on Friday, or in Lent, let us consider whether it be a small matter to corrupt and bastardize the service of God! For surely those that go about to set forth and establish the tradition of men, set themselves against that which God hath appointed in His Word, and thus commit sacrilege.

John Calvin
The Word Our Only Rule