Numbers 29:12

The Feast of Temporary Shelters

29:12 “‘On the fifteenth day of the seventh month you are to have a holy assembly; you must do no ordinary work, and you must keep a festival to the Lord for seven days.

Numbers 31:19

Purification After Battle

31:19 “Any of you who has killed anyone or touched any of the dead, remain outside the camp for seven days; purify yourselves and your captives on the third day, and on the seventh day.