1 Corinthians 10:8

Neither should we commit sexual immorality as some of them did, [with] 23,000 people falling dead in one day. [Note: Num. 25:9 mentions 24,000 people slain, but that number could have included the additional people slain by the judges. See Num. 25:5].

Hebrews 2:2-3

For if the message spoken through angels proved to be binding [Note: This is a reference to the law of Moses. See Acts 7:53; Gal. 3:19], and every violation [of it] and disobedience [to it] received a just penalty,

Treasury of Scripture Knowledge

Summary

And the children of Levi did according to the word of Moses: and there fell of the people that day about three thousand men.

Bible References

There fell

1 Corinthians 10:8
Neither should we commit sexual immorality as some of them did, [with] 23,000 people falling dead in one day. [Note: Num. 25:9 mentions 24,000 people slain, but that number could have included the additional people slain by the judges. See Num. 25:5].
Hebrews 2:2
For if the message spoken through angels proved to be binding [Note: This is a reference to the law of Moses. See Acts 7:53; Gal. 3:19], and every violation [of it] and disobedience [to it] received a just penalty,