Job 1:4-5

4And his sons would go and feast in their houses, each on his appointed day, and would send and invite their three sisters to eat and drink with them.

5So it was, when the days of feasting had run their course, that Job would send and sanctify them, and he would rise early in the morning and offer burnt offerings according to the number of them all. For Job said, “It may be that my sons have sinned and cursed God in their hearts.” Thus Job did regularly.