John Gill Commentary Joshua 20

The Lord also spoke to Joshua
Out of the tabernacle, at the door of which he with the high priest and princes were; the Lord has spoken to him before concerning dividing the land among the tribes, (Joshua 13:1–7); and this being done he speaks to him again:

saying :
as follows.

Speak to the children of Israel, saying
Whom the affair concerned the Lord spoke to Joshua about, they having now the whole land divided among them:

appoint out for you cities of refuge ;
of the name, nature, use, and number of these cities, (See Gill on Numbers 35:6);

whereof I spoke to you by the hand of Moses :
(Numbers 35:1–34) (Deuteronomy 19:1–21) .

That the slayer that killeth [any] person unawares, [and]
unwittingly, may flee thither
Who through mere accident, and without design, killed a person, friend or foe, one of his own kindred, or a stranger, without any malice against him, or intention to take away his life:

and they shall be your refuge from the avenger of blood ;
from any of the relations of the deceased, who might be stirred up to avenge the blood of his kinsman on the slayer; see (Numbers 35:12) .

And when he that doth flee unto one of those cities
Any one of them, that was nearest to him:

shall stand at the entering of the gate of the city ;
for he might not rush in without leave:

and shall declare his cause in the ears of the elders of that city ;
lay before them the whole matter, how that he had killed a person unawares, by what means it came about, and that it was merely through error, without any malicious design, and was a mere accident:

they shall take him into the city unto them ;
directly, lest the avenger of blood should come and seize on him, and kill him; and they were to take him into the city, not only to prevent that, but to examine him still more closely about the matter, and get further satisfaction; and being satisfied, were to continue him in it:

and give him a place, that he might dwell among them ;
until his death, or the death of the high priest, if that was first. Kimchi observes from their Rabbins, the he was not to hire a house all the time of his dwelling there, but was to have one freely, because it is said, "and give him"

And if the avenger of blood pursue after him
To the city of refuge, whither he is fled, and demand him:

then they shall not deliver the slayer up into his hands ;
to be slain by him, but shall protect him:

because he smote his neighbour unwittingly, and hated him not
beforetime; (See Gill on Numbers 35:22), (See Gill on Numbers 35:23), and (See Gill on Deuteronomy 19:6).