1 Corinthians 10:8

8.Neither let us commit fornication Now he speaks of fornication, in respect of which, as appears from historical accounts, great licentiousness prevailed among the Corinthians, and we may readily infer from what goes before, that those who had professed themselves to be Christ’s were not yet altogether free from this vice. The punishment of this vice, also, ought to alarm us, and lead us to bear in mind, how loathsome impure lusts are to God, for there perished in one day twenty-three thousand, or as Moses says, twenty-four. Though they differ as to number, it is easy to reconcile them, as it is no unusual thing, when it is not intended to number exactly and minutely each head, (546) to put down a number that comes near it, as among the Romans there were those that received the name of Centumviri , (547) (The Hundred,) while in reality there were two above the hundred. As there were, therefore, about twenty-four thousand that were overthrown by the Lord’s hand — that is, above twenty-three, Moses has set down the number above the mark, and Paul, the number below it, and in this way there is in reality no difference. This history is recorded in Numbers 25:9

There remains, however, one difficulty here — why it is that Paul attributes this punishment to fornication, while Moses relates that the anger of God was aroused against the people on this account — that they had initiated themselves in the sacred rites of Baalpeor. (548) But as the defection began with fornication, and the children of Israel fell into that impiety, not so much from being influenced by religious considerations, (549) as from being allured by the enticements of harlots, everything evil that followed from it ought to be attributed to fornication. For Balaam had given this counsel, that the Midianites should prostitute their daughters to the Israelites, with the view of estranging them from the true worship of God. Nay more, their excessive blindness, in allowing themselves to be drawn into impiety (550) by the enticements of harlots, was the punishment of lust. Let us learn, accordingly, that fornication is no light offense, which was punished on that occasion by God so severely and indeed in a variety of ways.