Here is the exchange made of the Levites for the first-born. 1. The first-born were numbered from a month old, Num. 3:42, 43. Those certainly were not reckoned who, though first-born, had become heads of families themselves, but those only that were under age; and the learned bishop Patrick is decidedly of opinion that none were numbered but those only that were born since their coming out of Egypt, when the first-born were sanctified, Exod. 13:2. If there were 22,000 first-born males, we may suppose as many females, and all these brought forth in the first year after they came out of Egypt, we must hence infer that in the last year of their servitude, even when it was in the greatest extremity, there were abundance of marriages made among the Israelites; they were not discouraged by the present distress, but married in faith, expecting that God would shortly visit them with mercy, and that their children, though born in bondage, should live in liberty and honour. And it was a token of good to them, an evidence that they were blessed of the Lord, that they were not only kept alive, but greatly increased, in a barren wilderness. 2. The number of the first-born, and that of the Levites, by a special providence, came pretty near to each other; thus, when he divided the nations, he set the bounds of the people according to the number of the children of Israel, Deut. 32:8. Known unto God are all his works beforehand, and there is an exact proportion between them, and so it will appear when they come to be compared. The Levites’ cattle are said to be taken instead of the firstlings of the cattle of the children of Israel, that is, the Levites, with all their possessions, were devoted to God instead of the first-born and all theirs; for, when we give ourselves to God, all we have passes as appurtenances with the premises. 3. The small number of first-born which exceeded the number of the Levites (273 in all) were to be redeemed, at five shekels apiece, and the redemption-money given to Aaron; for it would not do well to have them added to the Levites. It is probable that in the exchange they began with the eldest of the first-born, and so downward, so that those were to be redeemed with money who were the 273 youngest of the first-born; more likely so than either that it was determined by lot or that the money was paid out of the public stock. The church is called the church of the first-born, which is redeemed, not as these were, with silver and gold, but, being devoted by sin to the justice of God, is ransomed with the precious blood of the Son of God.