When the whole congregation saw that Aaron had died, the entire house of Israel mourned for him thirty days.
When the congregation sees that Aaron has died, the whole house of Israel mourns for him thirty days.
This verse closes the chapter with communal mourning.
22After they had set out from Kadesh, the whole congregation of Israel came to Mount Hor. 23And at Mount Hor, near the border of the land of Edom, the LORD said to Moses and Aaron, 24“Aaron will be gathered to his people; he will not enter the land that I have given the Israelites, because both of you rebelled against My command at the waters of Meribah. 25Take Aaron and his son Eleazar and bring them up Mount Hor. 26Remove Aaron’s priestly garments and put them on his son Eleazar. Aaron will be gathered to his people and will die there.” 27So Moses did as the LORD had commanded, and they climbed Mount Hor in the sight of the whole congregation. 28After Moses had removed Aaron’s garments and put them on his son Eleazar, Aaron died there on top of the mountain. Then Moses and Eleazar came down from the mountain. 29When the whole congregation saw that Aaron had died, the entire house of Israel mourned for him thirty days.