Charles Ellicott Commentary Numbers 35:12

"And the cities shall be unto you for refuge from the avenger, that the manslayer die not, until he stand before the congregation for judgment." — Numbers 35:12 (ASV)

And they shall be to you cities for refuge... — Better, And the cities shall be to you for refuge (or, as a place of refuge) from the avenger, that the manslayer may not die until he stands before the congregation for judgment. The avenger (Hebrew, goel) was the near kinsman whose office it was to redeem the person or inheritance of his kinsman, if that kinsman was reduced by poverty to sell himself into slavery or to sell his inheritance; and also to avenge his blood if he were slain. (See Leviticus 25:25-55, and Notes.)

The law of the goel, as contained in this chapter, served to keep in check the excited passions of the near relations of the man who had been slain, and to secure for him a fair and impartial trial. The duties that fell to the congregation are stated in Numbers 35:24-25. Christ, as our “Redeemer” (Hebrew, goel), ever lives (Job 19:25). He has redeemed the persons and the inheritance of His people by His death; and He will in the last great day, ransom them from the power of the grave, and redeem them from death (Hosea 13:4, where a cognate verb to goel occurs), and will avenge their blood on them that dwell on the earth (Revelation 6:10).