'Minister' in the Bible

Bring the tribe of Levi near, and present them before Aaron the priest, that they may minister unto him;

but he shall minister with his brethren in the tent of meeting, and keep the charge, but he shall not serve in the service. Thus shalt thou do unto the Levites with regard to their charges.

Is it too little for you, that the God of Israel has separated you from the assembly of Israel, to bring you near to himself to do the work of the tabernacle of Jehovah, and to stand before the assembly to minister to them?

And thy brethren also, the tribe of Levi, the tribe of thy father, bring near with thee, that they may unite with thee, and minister unto thee; but thou and thy sons with thee shall serve before the tent of the testimony.