1 Corinthians 10:8

Neither let us commit fornication, as some of them committed, and fell in one day three and twenty thousand. [Numbers 25:1-9. While Paul gives the number as twenty-three thousand, Moses gives it as twenty-four. Alford and Kling think the discrepancy is due to a failure in Paul's memory, but why should the Spirit of God let him thus forget? Grotius says that a thousand were slain by Phinehas and his followers, and the rest were destroyed by the plague. Kitto varies this a little by saying that Paul gives the number that fell on one day, as his words show, while Moses gives the full number that perished on both days. But Bengel's solution is a sufficient one. The Hebrews habitually dealt in round numbers, so that a number between twenty-three and twenty-four thousand could be correctly stated by either figure. Moses gave the maximum and Paul the minimum. The sin mentioned was not only an ordinary accompaniment of idolatry, but often a consecrated part of it, as in the rites of Baal-peor among the Moabites and those of Venus among the Corinthians. Sins are gregarious.]