'Seventh Day' in the Bible
“If someone suddenly dies near him, defiling his consecrated head of hair, he must shave his head on the day of his purification; he is to shave it on the seventh day.
On the seventh day Elishama son of Ammihud, leader of the Ephraimites, presented an offering.
He is to purify himself with the water on the third day and the seventh day; then he will be clean. But if he does not purify himself on the third and seventh days, he will not be clean.
“The one who is clean is to sprinkle the unclean person on the third day and the seventh day. After he purifies the unclean person on the seventh day, the one being purified must wash his clothes and bathe in water, and he will be clean by evening.
On the seventh day you are to hold a sacred assembly; you are not to do any daily work.
“On the seventh day present seven bulls, two rams, and 14 male lambs a year old—all unblemished—
“You are to remain outside the camp for seven days. All of you and your prisoners who have killed a person or touched the dead are to purify yourselves on the third day and the seventh day.
On the seventh day wash your clothes, and you will be clean. After that you may enter the camp.”