John Gill Commentary Joshua 20:5

"And if the avenger of blood pursue after him, then they shall not deliver up the manslayer into his hand; because he smote his neighbor unawares, and hated him not beforetime." — Joshua 20:5 (ASV)

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).