Treasury of Scripture Knowledge

Summary

Both to the genealogy of the priests by the house of their fathers, and the Levites from twenty years old and upward, in their charges by their courses;

Bible References

Genealogy

Numbers 3:15
Number thou the sons of Levi, by their ancestral houses, by their families, - every male, from one month old and upwards, shalt thou number them.
Numbers 4:38
And they who were numbered of the sons of Gershon, - by their families, and by their ancestral house;
Numbers 17:2
Speak unto he sans of Israel and take of them one staff each for an ancestral house of all their princes, by their ancestral houses, twelve staves, - each man's name, shalt thou write upon his staff;
Ezra 2:59
And, these, were they who came up from Tel-melah, Tel-harsha, Cherub, Addan, Immer; but they could not tell their ancestral house, nor their seed, whether, of Israel, they were:

Twenty

Numbers 4:3
from thirty years old, and upwards, even unto fifty years, - every one that can enter into the host, to do service in the tent of meeting.
Numbers 8:24
This is what concerneth the Levites, - from twenty-five years old and upwards, shall they enter to take rank in the host, for doing the laborious work of the tent of meeting;
1 Chronicles 23:24
These, were the sons of Levi by their ancestral house, the ancestral chiefs of them who were counted in the number of their names, by their polls, doing the work, for the service of the house of Yahweh, - from twenty years old, and upwards.

By their courses

2 Chronicles 31:2
And Hezekiah appointed the courses of the priests, and the Levites, over their courses, every man according to the requirements of his service, both priests and Levites, for ascending-sacrifice and for peace-offerings, - to be in attendance and to give thanks and to offer praise, in the gates of the camps of Yahweh;
1 Chronicles 24:20
Now, as for the sons of Levi who remained, of the sons of Amram, Shubael, of the sons of Shubael, Jehdeiah.