Numbers 16:5

And he spake unto Korah, and unto all his company
The two hundred fifty princes that were with him; what follows was said to them apart from Dathan and Abiram, who seem not to be present at this time; and this was after Moses had finished his prayer to God, and had received instructions from him, by an impulse on his mind, what he should say unto them, and was now risen up from the earth he fell upon:

saying, even tomorrow the Lord will show who [are] his;
his priests, whom he had chosen, and put into that office; this he would make known so clearly and plainly, that there would be no room left to doubt of it, and which was revealed to Moses while upon his face in prayer to God:

and [who is] holy;
or whom he has separated to such an holy office and service:

and will cause [him] to come near unto him;
and do his work as a priest, without fear of danger, and without any hurt, which is suggested would befall others; and they may expect it, who intrude themselves into such an office, and engage their hearts in a bold audacious manner, to draw nigh to God in it:

even [him] whom he hath chosen will he cause to come near unto him:
meaning Aaron with his sons, whom the Lord would make to appear that he had chosen, and put into the office of priesthood, and that it was not what Moses did of himself.