Charles Ellicott Commentary Exodus 21:13

"And if a man lie not in wait, but God deliver [him] into his hand; then I will appoint thee a place whither he shall flee." — Exodus 21:13 (ASV)

If a man lie not in wait, but God deliver him into his hand. —This means if, without malice aforethought, a man encounters his enemy, God’s providence bringing the two into contact without human planning, and the result is that one kills the other, then the law of refuge or asylum will apply.

A place is to be provided where the manslayer can flee and be safe, at least until the case is investigated.

Previously, throughout the East, it had been regarded as the duty of the next of kin to avenge any kind of homicide, and blood was exacted for blood, however sudden, provoked, or excusable the homicide had been.

No right of asylum, so far as we know, had ever been established before. The Sinaitic legislation, for the first time, introduced the “city of refuge” between the “avenger of blood” and his victim. It was for the elders of the city to ensure that the privilege was not abused. If the case was doubtful, the manslayer had to be sent for trial to the elders of his own town (Numbers 35:22–25); if the elders considered his claim substantiated, he was entitled to protection.