In Context

18 Ye shall not cut off the families of the Kohathites from among the Levites,

19 but this shall ye do unto them, that they may live, and not die, when they draw near unto the most holy things: Aaron and his sons shall go in, and appoint them every one to his service and to his burden;

20 but they shall not go in and see for a moment the holy things, lest they die.

21 And Jehovah spoke to Moses, saying,

22 Take also the sum of the sons of Gershon, according to their fathers' houses, after their families.

23 From thirty years old and upward to fifty years old shalt thou number them; every one that cometh to labour in the work, to perform the service in the tent of meeting.

Numbers 4:21 in Other Translations