Numbers 4:2-3
4:2 “Take a census of the Kohathites from among the Levites, by their families and by their clans,
4:3 from thirty years old and upward to fifty years old, all who enter the company to do the work in the tent of meeting.
Numbers 4:23
4:23 You must number them from thirty years old and upward to fifty years old, all who enter the company to do the work of the tent of meeting.
Numbers 4:30
4:30 You must number them from thirty years old and upward to fifty years old, all who enter the company to do the work of the tent of meeting.
Numbers 4:35
4:35 from thirty years old and upward to fifty years old, everyone who entered the company for the work in the tent of meeting;
Numbers 4:43
4:43 from thirty years old and upward to fifty years old, everyone who entered the company for the work in the tent of meeting –
Numbers 4:47
4:47 from thirty years old and upward to fifty years old, everyone who entered to do the work of service and the work of carrying relating to the tent of meeting –