The sacrifices were wisely appropriated to that one and public place, partly for the security of the true religion, and for the prevention of idolatry and superstition, which otherwise might more easily have crept in; and partly to signify that their sacrifices were not accepted for their own worth, but by God's gracious appointment, and for the sake of God's altar, by which they were sanctified, and for the sake of Christ, whom the altar did manifestly represent. Of tithes, See Poole on "Deuteronomy 12:17". Heave-offerings, i.e. your first-fruits, to wit, of the earth, as of corn and wine and oil and other fruits, as plainly appears by comparing this place with Deuteronomy 18:4, Deuteronomy 26:2, where these are commanded to be brought thither; and seeing here is an exact and particular enumeration of all such things, and these cannot be put under any of the other branches, these must needs be intended here, the rather because the other kind of first-fruits, to wit, of the herds and flocks, are here expressly mentioned. And these are called here the heave-offerings of their hand, because the offerer was first to take these into his hands, and to heave them before the Lord, (as other places tell us,) and then to give them to the priest, as appears from Deuteronomy 18:3,4 Deuteronomy 26:4. Your free-will offerings; even for your voluntary oblations, which were not due by my prescription, but only by your own choice and voluntary engagement: you may choose what kind of offering you please to vow and offer, but not the place where you shall offer them. The firstlings of your herds and of your flocks; either,
1. The holy firstlings or first-born, as appears by Num 18, where they are commanded to be brought to this one place here designed, and to be offered upon God's altar, Deuteronomy 12:17. It is objected by some, that those were given to the priests, Numbers 18:18, but these were to be eaten by the people here, Deuteronomy 12:7. But that the next verse doth not say, but only in general, there shall ye eat, to wit, such of the offerings mentioned Deuteronomy 12:6 as they were allowed to eat, but not such as were the priest's peculiar, for these they might not eat, nor all there expressed; for it is evident they might not eat any of the burnt-offerings, nor some parts of the other sacrifices, which are here mentioned. Or,
2. The second births, which were the people's first-born, or the first which they could eat of, which they were to eat before the Lord by way of acknowledgment of his favour in giving them to them and all their succeeding births. See more on Deuteronomy 12:17.