Moses
Numbers 3:9ESV·traditional attribution

And you shall give the Levites to Aaron and his sons; they are wholly given to him from among the people of Israel.

Matthew Henry Presbyterian @wholebiblehenry

Here, I. The family of Aaron is confirmed in the priests' office, Num 3:10. They had been called to it before, and consecrated; here they are appointed to wait on their priests' office: the apostle uses this phrase (Rom 12:7), Let us wait on our ministry.

Commenting on Numbers 3:1-13

John Gill Reformed Baptist @doctorgill

And thou shalt give the Levites unto Aaron and to his sons,.... To be their ministers and servants: they are wholly given unto him out of the children of Israel: even all of them entirely, none excepted; the whole tribe which were not in the priestly office; those were separated from the rest of the tribes of Israel, and appointed for the service of the...

Jamieson-Fausset-Brown Reformed @jfbcommentary

they are wholly given unto him out of the children of Israel, &c.--The priests hold the place of God, and the Levites are the servants of God in the obedience they render to the priests.