Peter all but pleads for himself, when at the point to inflict the punishment, and at the same time gives a lesson to the rest. For because the act would seem exceeding stern, therefore it is that he does so much in the case. In respect of the woman also the process of judgment was terrible. But see how many evils grow out of the sacrilege: covetousness, contempt of God, impiety; and upon these too he pleaded for himself before the assembly, in that he did not immediately proceed to punishment, but first exposed the sin. None groaned, none lamented, all were terrified. For as their faith increased, the signs also were multiplied, and great was the fear among their own company: for the things which are from without do not so militate (πολεμεἵ) against our peace, as do the acts of our own people. If we be firmly joined together, no warfare will be hard: but the mischief would be the being divided and broken up. Now they went about in the public place: with boldness they attacked even the market, and in the midst of enemies they prevailed, and that saying was fulfilled, “Be Thou Ruler in the midst among Your enemies.” This was a greater miracle, that they, arrested, cast into prison, should do such acts as these!
If those for lying suffered such things, what shall not the perjured suffer? Because she simply affirmed, “Yea, for so much,” ye see what she suffered. Bethink you then; they that swear and forswear themselves, of what should they be worthy? It comes in opportunely today even from the Old Testament to show you the heinousness of perjury. “There was,” it says, “a flying sickle, ten cubits in breadth.” The “flying” betokens the swift advent of the vengeance which pursues oaths; that it is many cubits in length and breadth, signifies the force and magnitude of the woes; that it comes flying “from heaven,” is to show that the vengeance comes from the judgment-seat on high: that it is in the form of a sickle, denotes the inevitableness of the doom: for just as the sickle, where it comes and has hooked the neck, is not drawn back with nothing but itself, but with the head reaped off, even so the vengeance which comes upon the swearers is severe, and will not desist until it have completed its work. But if we swear and escape, let us not be confident; this is but to our woe. For what think ye? How many, since Ananias and Sapphira, have dared the same with them? How is it then, say you, that they have not met with the same fate? Not because it was allowed in them, but because they are reserved for a greater punishment. For those who often sin and are not punished, have greater reason to fear and dread than if they were punished. For the vengeance is increased for them by their present impunity and the long-suffering of God. Then let us not look to this, that we are not punished; but let us consider whether we have not sinned: if sinning we are not punished, we have the more reason to tremble. Say, if you have a slave, and you only threaten him, and do not beat him; when is he most in fear, when most inclined to run away? Is is not when you only threaten him? And hence we advise each other not to be continually using threats, thereby choosing rather to agitate the mind by the terror, and lacerating it worse than with blows. For in the one instance the punishment is momentary, but in the other it is perpetual. If then no one feels the stroke of the sickle, do not look to this, but rather let each consider whether he commits such sins. Many like things are done now as were done before the Flood, yet no flood has been sent: because there is a hell threatened, and vengeance. Many sin as the people did in Sodom, yet no rain of fire has been poured down; because a river of fire is prepared. Many go the lengths of Pharaoh; yet they have not fared like Pharaoh, they have not been drowned in a Red Sea: for the sea that awaits them, is the sea of the bottomless pit, where the punishment is not accompanied with insensibility, where there is no suffocation to end all, but in ever lengthened torture, in burning, in strangling, they are consumed there. Many have offended like the Israelites, but no serpents have devoured them: there awaits them the worm that never dies. Many have been like Gehazi, yet they have not been struck with leprosy: for instead of leprosy, it remains for them to be cut asunder, and numbered among the hypocrites. Many have both sworn and forsworn; but if they have indeed escaped, let us not be confident: the gnashing of teeth awaits them. Yea, here too they will suffer many grievous woes, though, it may be, not immediately, but after further transgressions, that the vengeance may be the greater; for even we often set out at first with small sins, and then through great offenses lose all. Therefore when you see anything happening to you, call to mind that particular sin of yours. The sons of Jacob are an example of this. Remember Joseph's brothers; they had sold their brother, they had even attempted to slay him; nay, they had slain him, as far as inclination went; they had deceived and grieved the old man; they suffered nothing. After many years they are brought into extreme peril, and now they are put in remembrance of this their sin. Exceeding wisely is this circumstance brought in. Hear what they say: “We are verily guilty concerning our brother.” In this manner then do thou also, when anything happens, say, We are verily guilty, because we have not obeyed Christ; because we have sworn; my much swearing, and my false swearing, has fallen upon my own head. Confess thou; since they also confessed, and were saved. For what though the punishment follow not immediately? Since Ahab also did not immediately after his sin in the matter of Naboth suffer that vengeance which he yet at last suffered. And what is the reason of this? God sets you a time, in which to wash yourself clean; but if you persist, at last He will send down the vengeance. You have seen the fate of liars. Consider what is the fate of false swearers, consider, and desist. It is impossible a swearer should not forswear himself, whether he will or not; and no perjurer can be saved. One false oath suffices to finish all, to draw down upon us the whole measure of vengeance. Let us then take heed to ourselves, that we may escape the punishment due to this offense, and be deemed worthy of the loving kindness of God, through the grace and mercies of His only-begotten Son, with Whom to the Father and the Holy Ghost be glory, power, and honor, now and ever, and world without end. Amen.
Source: Homilies on Acts (New Advent)