Mourning: Caused Ceremonial Defilement
Source: Nav
Numbers 19:11–16
Whoever touches any dead body will be unclean for seven days. / He must purify himself with the water on the third day and on 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. / Anyone who touches a human corpse and fails to purify himself defiles the tabernacle of the LORD. That person must be cut off from Israel. He remains unclean, because the water of purification has not been sprinkled on him, and his uncleanness is still on him.
Numbers 31:19
All of you who have killed a person or touched the dead are to remain outside the camp for seven days. On the third day and the seventh day you are to purify both yourselves and your captives.
Leviticus 21:1
Then the LORD said to Moses, “Speak to Aaron’s sons, the priests, and tell them that a priest is not to defile himself for a dead person among his people,