Numbers Chapter 8 on Distinction of the Tribes of Levy with Strict Purity

The Service Of The Sons Of Aaron And The Levites Are Clearly Of G-d’s Origin

Hence, to render service to G-d is far more noble than simply doing good deeds.

For it requires purity, sanctity and consecration.

“The Menorah”
“Consecration of the Levites”
“Apprenticeship and Responsibility”

Hashem spoke to Moses, saying, “Speak to Aaron and say to him: When you kindle the lamps, toward the face of the Menorah shall the seven lamps cast light.”
8:1-2
This is the workmanship of the Menorah, hammered-out gold, from its base to its flower it is hammered out; according to the vision that Hashem showed Moses, so did he make the Menorah.
:4
So shall you do to them to purify them: Sprinkle upon them water of purification, and let them pass a razor over their entire flesh, and let them immerse their garments, and they shall become pure.
:7
They shall take a young bull and its meal-offering, fine flour mixed with oil, and a second young bull and its meal-offering.
:8
You shall bring the Levites before Hashem, and the Children of Israel shall lean their hands upon the Levites.
:10
So shall you separate the Levites from among the Children of Israel, and the Levites shall remain Mine.
:14
For presented, presented are they to Me from among the Children of Israel; in place of the first issue of every womb, the firstborn of everyone of the Children of Israel, have I taken them to Myself.
:16
I took the Levites in place of every firstborn among the Children of Israel.
:18
Then I assigned the Levites to be presented to Aaron and his sons from among the Children of Israel to perform the service of the Children of Israel in the Tent of Meeting and to provide atonement for the Children of Israel, so that there will not be a plague among the Children of Israel when the Children of Israel approach the Sanctuary.”
:19
Moses, Aaron, and the entire assembly of the Children of Israel did to the Levites according to everything that Hashem had commanded Moses about the Levites, so did the Children of Israel do to them.
:20
Hashem spoke to Moses, saying, “This shall apply to the Levites: From twenty-five years of age and up, he shall join the legion of the service of the Tent of Meeting.
:23-24
From fifty years age, he shall withdraw from the legion of work and no longer work.
:25
He shall minister with his brethren in the Tent of Meeting to safeguard the charge, but work shall he not perform. So shall you do to the Levites concerning their charge.”
:26

1 The Lord spoke to Moses, saying:
2 Speak to Aaron and say to him: “When you light the lamps, the seven lamps shall cast their light toward the face of the menorah.”
3 Aaron did so; he lit the lamps toward the face of the menorah, as the Lord had commanded Moses.
4 This was the form of the menorah: hammered work of gold, from its base to its flower it was hammered work; according to the form that the Lord had shown Moses, so did he construct the menorah.
5 The Lord spoke to Moses saying:
6 Take the Levites from among the children of Israel and cleanse them.
7 This is what you shall do to them so as to cleanse them: sprinkle them with cleansing water and pass a razor over all their flesh; then they shall wash their garments and cleanse themselves.
8 Then they shall take a young bull with its meal offering of fine flour mingled with oil. And you shall take a second young bull as a sin offering.
9 You shall bring the Levites in front of the Tent of Meeting, and you shall gather the entire congregation of the children of Israel.
10 You shall bring the Levites before the Lord, and the children of Israel shall lay their hands upon the Levites.
11 Then Aaron shall lift up the Levites as a waving before the Lord on behalf of the children of Israel, that they may serve in the Lord’s service.
12 The Levites shall lay their hands on the heads of the bulls, and make one as a sin offering and one as a burnt offering to the Lord, to atone for the Levites.
13 You shall present the Levites before Aaron and his sons, and lift them as a waving before the Lord.
14 Thus shall you set apart the Levites from the midst of the children of Israel, and the Levites shall become Mine.
15 Following this, the Levites shall come to serve in the Tent of Meeting. You shall cleanse them and lift them as a waving.
16 For they are wholly given over to Me from among the children of Israel; instead of those that open the womb all the firstborn of Israel I have taken them for Myself.
17 For all the firstborn among the children of Israel are Mine whether man or beast since the day I smote all the firstborn in the land of Egypt; I have sanctified them for Myself.
18 And I have taken the Levites instead of all the firstborn of the children of Israel.
19 I have given the Levites as a gift to Aaron and his sons from among the children of Israel, to perform the service for the children of Israel in the Tent of Meeting and to atone on behalf of the children of Israel, so that the children of Israel will not be inflicted with plague when they approach the Sanctuary.
20 So Moses, Aaron, and the entire congregation of Israel did [this] to the Levites; the children of Israel did [in accordance with] all that the Lord had instructed Moses regarding the Levites.
21 The Levites cleansed themselves and washed their clothes. Then Aaron lifted them as a waving before the Lord, and Aaron atoned for them to cleanse them.
22 After that, the Levites came to perform the service in the Tent of Meeting before Aaron and before his sons; they did to them just as the Lord had commanded Moses regarding the Levites.
23 The Lord spoke to Moses saying:
24 This is [the rule] concerning the Levites: From the age of twenty five years and upwards, he shall enter the service to work in the Tent of Meeting.
25 From the age of fifty he shall retire from the work legion, and do no more work.
26 He shall minister with his brethren in the Tent of Meeting to keep the charge, but he shall not perform the service; thus shall you do for the Levites regarding their charge.