John Gill Bible Commentary

And if a man lie not in wait,.... For the life of another to take it away; or does not do it willingly, as the Septuagint version, does not seek after it, nor design it: but God delivers him into his hand; it being suffered and ordered by the providence of God, without whose knowledge and will nothing comes to pass, even what may seem to be a contingent thing, or matter of chance, to us; or it is so brought about in providence, that one man falls into the hands of another, and his life is taken away by him, though not purposely and maliciously; because, as Aben Ezra expresses it, for another sin which he has committed, and for which he must die in this way, though not intended by the person the more immediate cause of his death: then I will appoint thee a place whither he shall flee; and there be safe both from the avenger of blood, and the civil magistrate; which place, while Israel were in the wilderness, was the camp of the Levites, according to Jarchi, or the altar, as follows; but when they were come to Canaan's land, there were cities of refuge appointed for such persons, that killed a man unawares, to flee to, and where they were safe from private vengeance, and falling a sacrifice to public justice.