1 Corinthians 10:8

10:8 And let us not be immoral, as some of them were, and twenty-three thousand died in a single day. ¹ 

1 Corinthians 10:11

10:11 These things happened to them as examples and were written for our instruction, on whom the ends of the ages have come.

[10:8]  ¹ sn This incident is recorded in Num 25:1-9.