John Gill Commentary Numbers 5

And the Lord spoke to Moses
Jarchi says, what follows was said on the day the tabernacle was erected, but it seems rather to have been delivered after the several camps were formed, and the people numbered, when those that were unclean were ordered to be cast out of them:

saying ;
as follows.

Command the children of Israel
Not as from himself, but from the Lord; deliver out the following as a command of his, to which obedience was required of all the children of Israel:

that they put out of the camp every leper ;
there were three camps, Jarchi says, in the time of their encampment; between the curtains was the camp of the Shechinah, or the divine Majesty; the encampment of the Levites round about; and from thence to the end was the camp of the standards, to the four winds, which was the camp of Israel; and the leper was to be put out of them all; so Ben Gersom; see (Leviticus 13:46) ;

and everyone that has an issue ;
a gonorrhoea, man or woman, see (Leviticus 15:2Leviticus 15:19) ; according Jarchi, such an one might be in the camp of Israel, but was to be put out of the other two camps:

and whosoever is defiled by the dead ;
by attending the funerals of the dead, or touching them, see (Leviticus 21:1) (22:4) ; such an one might go into the camp of the Levites, according to Jarchi and Ben Gersom; and was to be put of none but the camp of the Shechinah, or the tabernacle; but the camp of Israel seems to be meant of them all, out of which they were to be put, as an emblem of the rejection of all impure persons out of the church of God.

Both male and female shall you put out
Whether leprous, or profluvious, or defiled by touching a dead carcass: by this law, Miriam, when leprous, was put out of the camp, (Numbers 12:14Numbers 12:15) ;

without the camp shall you put them ;
which is repeated that it might be taken notice of, and punctually observed:

that they defile not your camps ;
of which there were four, the camps of Judah, Reuben, Ephraim, and Dan:

in the midst whereof I dwell ;
for the tabernacle, which was the dwelling place of the Lord, was in the midst of the camps of Israel; they were pitched on the four quarters of it; and this is a reason why impure persons were not suffered to be in the camp of Israel, because of the presence of God in the tabernacle so near them, to whom all, impurity is loathsome, and not to be permitted in his sight; and though this was ceremonial, it was typical of the uncleanness of sin, which is abominable to him, and renders persons unfit for communion with him, and with his people.

And the children of Israel did so, and put them without the
camp
Aben Ezra observes, that this was done immediately before they journeyed, and that those that were defiled journeyed between the standard of Ephraim and the standard of Dan; but this, he says, was by way of conjecture, since it is not expressed:

as the Lord spoke to Moses, so did the children of Israel ;
they were obedient in this particular.

And the Lord spoke to Moses: Or continued to speak to him at the same time: saying; as follows.