Joel 2:15

Here again the Prophet reminds them that there was need of deep repentance; for not only individuals had transgressed, but the whole people had become guilty before God; and we also know how many and grievous their sins had been. There is no wonder then that the Prophet requires a public profession of repentance.

He bids them first to sound the trumpet in Zion. This custom, as we have seen at the beginning of the chapter, was in common use under the Law; they summoned their meetings by the sound of trumpets. There is then no doubt but that the Prophet here refers to an extraordinary meeting. They sounded the trumpets whenever they called the people to the festivals. But it must have been unusual for the Jews to proclaim a fast on account of God’s heavy judgment, which was to come on them unless it was prevented. He then shows the purpose of this, bidding them to sanctify a fast By this word קדש kodesh, he means a proclamation for a holy purpose. Sanctify, then a fast, that is, Proclaim a fast in the name of God.

We slightly touched on the subject of fasting in the first chapter, but deferred a fuller discussion to this place. Fasting, we know, is not of itself a meritorious work, as the Papists imagine it to be: there is, indeed, strictly speaking, no work meritorious. But the Papists dream that fasting, in addition to its merit and worth, is also by itself of much avail in the worship of God; and yet fasting, when regarded in itself is an indifferent work. (5) It is not then approved by God, except for its end; it must be connected with something else, otherwise it is a vain thing. Men, by private fastings prepare themselves for the exercise of prayer, or they mortify their own flesh, or seek a remedy for some hidden vices. Now I do not call fasting temperance; for the children of God, we know, ought through their whole life to be sober and temperate in their habits; but fasting, I regard that to be, when something is abstracted from our moderate allowance: and such a fast, when practiced privately, is, as I have said, either a preparation for the exercise of prayer, or a means to mortify the flesh, or a remedy for some vices.

But as to a public fast, it is a solemn confession of guilt, when men suppliantly approach the throne of God, acknowledge themselves worthy of death, and yet ask pardon for their sins. Fasting then, with regard to God, is similar to black and mean garments and a long beard before earthly judges. The criminal goes not before the judge in a splendid dress, with all his fine things, but casts away every thing that was before elegant in his appearance, and by his uncombed hair and long beard he tries to excite the compassion of his judge. There is, at the same time, another reason for fasting; for when we have to do with men, we wish to please their eyes and conciliate their favor; and he who fasts, not only testifies openly that he is guilty, but he also reminds himself of his guilt; for as we are not sufficiently touched by the sense of God’s wrath, those aids are useful which help to excite and affect us. He then who fasts, excites himself the more to penitence.

We now perceive the right use of fasting. But it is of public fasting that the Prophet speaks here. For what purpose? That the Jews, whom he had before summoned, might present themselves before God’s tribunal, and that they might come there, not with vain excuses, but with humble prayer. This is the design of fasting. We now see how foolishly the Papists have abused fasting; for they think it to be a meritorious work; they imagine that God is honored by abstinence from meat; they also mention those benefits of fasting to which I have referred; but they join fasts with festivals, as if there was some religion in abstaining from flesh or certain meats. We now then perceive by what gross puerilities the Papists trifle with God. We must then carefully notice the end in view, whenever the Scripture speaks of fasting; for all things will be confounded, except we lay hold on the principle which I have stated — that fasting ought ever to be connected with its end. We shall now proceed.