And if the Lord thy God enlarge thy coast,.... Extend it further than it was upon their first settlement, even carry it as far as the river Euphrates, as in the times of Solomon, 1 Kings 4:21. Jarchi interprets it of such an enlargement as to give them the land of the Kenites, the Kenizzites and Kadmonites:

(as he hath sworn unto thy fathers), and give thee all the land which he promised to give unto thy, fathers: Abraham, Isaac, and Jacob; see Genesis 15:19.

And if the LORD thy God {d} enlarge thy coast, as he hath sworn unto thy fathers, and give thee all the land which he promised to give unto thy fathers;

(d) When you go over Jordan to possess the whole land of Canaan.

19:8 Enlarge thy coast - As far as Euphrates.

8, 9. And if the Lord thy God enlarge thy coast-Three additional sanctuaries were to be established in the event of their territory extending over the country from Hermon and Gilead to the Euphrates (see Ge 15:18; Ex 23:31). But it was obscurely hinted that this last provision would never be carried into effect, as the Israelites would not fulfil the conditions, namely, "that of keeping the commandments, to love the Lord, and walk ever in his ways." In point of fact, although that region was brought into subjection by David and Solomon, we do not find that cities of refuge were established; because those sovereigns only made the ancient inhabitants tributary, instead of sending a colony of Israelites to possess it. The privilege of sanctuary cities, however, was given only for Israelites; and besides, that conquered territory did not remain long under the power of the Hebrew kings.

19:1-13 Here is the law settled between the blood of the murdered, and the blood of the murderer; provision is made, that the cities of refuge should be a protection, so that a man should not die for that as a crime, which was not his willing act. In Christ, the Lord our Righteousness, refuge is provided for those who by faith flee unto him. But there is no refuge in Jesus Christ for presumptuous sinners, who go on still in their trespasses. Those who flee to Christ from their sins, shall be safe in him, but not those who expect to be sheltered by him in their sins.