So these [things] shall be for a (l) statute of judgment unto you throughout your generations in all your dwellings.
(l) A law to judge murders done either on purpose, or accidentally.

So these things shall be for a statute of judgment unto you,.... A judicial law, according to which they were to proceed in all the above cases:
throughout your generations in all your dwellings; throughout all ages, as long as they dwelt in the land of Canaan, even unto the times of the Messiah, in whom the things figured hereby had their accomplishment: the cities of refuge were types of Christ: hence a divine person, even the Messiah, is often spoken of as the refuge of his people, Psalm 9:9 with which compare Hebrews 6:18 these were places to flee to, as the word is rendered by the Greek version; to Christ sensible sinners flee for shelter and safety, which supposes danger in themselves from the law and justice of God; a sense of that danger which makes them flee from wrath to come; a view of Christ, as a place of refuge, and that no other but he will serve their purpose, and therefore make all the haste and speed they can unto him. The word properly signifies cities of gathering, or of reception. There was a gathering of the elect of God to Christ at his death; and there is another at effectual calling, which is an act of God's grace, and a distinguishing one, when souls gather to Christ as their Saviour for righteousness, peace, pardon, rest, and everlasting life; and when Christ receives them, though sinners, into his arms, and into his heart, and into open fellowship with him, so as to dwell in him, where they dwell pleasantly and safely; he receives them into his house here, and into heaven hereafter; and by, and in Christ, those that flee to him, and are received by him, are retained and preserved from Satan, law, hell and death. The cities of refuge were of God's appointing; so Christ, as a Saviour, and rock of refuge to his people, is appointed and foreordained of God; they were well known for refuges, as the Lord is in the places of Zion; they were open for all, at all times, as Christ is for all sinners, even the chief of sinners, Jews or Gentiles; they are all one in Christ, the Israelite, and the stranger and sojourner; all impediments were removed out of the way of them, and plain directions to them given, as are in the Gospel, and by the ministers of it; and there is always room in Christ for such that flee to him, as there was in those cities; and being in him, they are safe from the curse and condemnation of the law, from wrath to come, and from the second death; and their redemption and atonement, peace and reconciliation, liberty, life and salvation, are owing to the death of Christ, their high priest. Abendana (a) observes, that the death of the high priest atoned for the offence (of manslaughter), which was the reason the manslayer continued in the city of refuge till his death, and then was released: however, certain it is, that the death of Christ, our high priest, atones for every sin of those that flee to him, and by which they are reconciled to God. In some things there is a difference between these cities of refuge and Christ; they were six, he but one; they were for such only who shed blood ignorantly, he for such that were enemies to him, and lived in malice towards others, and guilty of the most enormous crimes: to be in these cities of refuge was a kind of exile and imprisonment, but they that are in Christ are freemen; it was possible that such might die that were in them, and at most were only delivered from temporal death, but they that flee to Christ for refuge are saved with an everlasting salvation.
(a) Not. in Miclol Yophi in ver. 25.

these things shall be for a statute of judgment unto you throughout your generations--The law of the blood-avenger, as thus established by divine authority, was a vast improvement on the ancient practice of Goelism. By the appointment of cities of refuge, the manslayer was saved, in the meantime, from the blind and impetuous fury of vindictive relatives; but he might be tried by the local court, and, if proved guilty on sufficient evidence, condemned and punished as a murderer, without the possibility of deliverance by any pecuniary satisfaction. The enactment of Moses, which was an adaptation to the character and usages of the Hebrew people, secured the double advantage of promoting the ends both of humanity and of justice.

If, therefore, the confinement of the unintentional manslayer in the city of refuge was neither an ordinary exile nor merely a means of rescuing him from the revenge of the enraged goel, but an appointment of the just and merciful God for the expiation of human blood even though not wilfully shed, that, whilst there was no violation of judicial righteousness, a barrier might be set to the unrighteousness of family revenge; it was necessary to guard against any such abuse of this gracious provision of the righteous God, as that into which the heathen right of asylum had degenerated.
(Note: On the asyla, in general, see Winer's Real-Wrterbuch, art. Freistatt; Pauly, Real-encyckl. der class. Alterthums-wissenschaft, Bd. i. s. v. Asylum; but more especially K. Dann, "ber den Ursprung des Asylrechts und dessen Schicksale und Ueberreste in Europa," in his Ztschr. fr deutsches Recht, Lpz. 1840. "The asyla of the Greeks, Romans, and Germans differed altogether from those of the Hebrews; for whilst the latter were never intended to save the wilful criminal from the punishment he deserved, but were simply established for the purpose of securing a just sentence, the former actually answered the purpose of rescuing the criminal from the punishment which he legally deserved.")
The instructions which follow in Numbers 35:29-34 were intended to secure this object. In Numbers 35:29, there is first of all the general law, that these instructions (those given in vv. 11-28) were to be for a statute of judgment (see Numbers 27:11) for all future ages ("throughout your generations," see Exodus 12:14, Exodus 12:20). Then, in Numbers 35:30, a just judgment is enforced in the treatment of murder. "Whoso killeth any person (these words are construed absolutely), at the mouth (the testimony) of witnesses shall the murderer be put to death; and one witness shall not answer (give evidence) against a person to die;" i.e., if the taking of life were in question, capital punishment was not to be inflicted upon the testimony of one person only, but upon that of a plurality of witnesses. One witness could not only be more easily mistaken than several, but would be more likely to be partial than several persons who were unanimous in bearing witness to one and the same thing. The number of witnesses was afterwards fixed at two witnesses, at least, in the case of capital crimes (Deuteronomy 17:6), and two or three in the case of every crime (Deuteronomy 19:15; cf. John 8:17; 2-Corinthians 13:1; Hebrews 10:28). - Lastly (Numbers 35:31.), the command is given not to take redemption money, either for the life of the murderer, who was a wicked man to die, i.e., deserving of death (such a man was to be put to death); nor "for fleeing into the city of refuge, to return to dwell in the land till the death of the high priest:" that is to say, they were neither to allow the wilful murderer to come to terms with the relative of the man who had been put to death, by the payment of a redemption fee, and so to save his life, as is not unfrequently the case in the East at the present day (cf. Robinson, Pal. i. p. 209, and Lane's Manners and Customs); nor even to allow the unintentional murderer to purchase permission to return home from the city of refuge before the death of the high priest, by the payment of a money compensation.