The explanation of this peculiar regulation is to be found in a special application of the principle which rules throughout the law; that the first-fruit, whether the first-born of man or beast, or the first-fruits of the field, shall always be consecrated unto God. But in this case the application of the principle is modified by the familiar fact that the fruit of a young tree, for the first few years of its bearing, is apt to be imperfect; it is not yet sufficiently grown to yield its best possible product. Because of this, in those years it could not be given to the Lord, for He must never be served with any but the best of everything; and thus until the fruit should reach its best, so as to be worthy of presentation to the Lord, the Israelite was meanwhile debarred from using it. During these three years the trees are said to be "as uncircumcised;" _i.e._, they were to be regarded as in a condition analogous to that of the child who has not yet been consecrated, by the act of circumcision, to the Lord. In the fourth year, however, the trees were regarded as having now so grown as to yield fruit in perfection; hence, the principle of the consecration of the first-fruit now applies, and all the fourth year's product is given to the Lord, as an offering of thankful praise to Him whose power in nature is the secret of all growth, fruitfulness, and increase. The last words of this law, "that it may yield unto you its increase," evidently refer to all that precedes. Israel is to obey this law, using nothing till first consecrated to the Lord, in order to a blessing in these very gifts of God. The moral teaching of this law, when it is thus read in the light of the general principle of the consecration of the first-fruits, is very plain. It teaches, as in all analogous cases, that God is always to be served before ourselves; and that not grudgingly, as if an irksome tax were to be paid to the Majesty of heaven, but in the spirit of thanksgiving and praise to Him, as the Giver of "every good and perfect gift." It further instructs us in this particular instance, that the people of God are to recognise this as being true even of all those good things which come to us under the forms of products of nature. The lesson is not an easy one for faith; for the constant tendency, never stronger than in our own time, is to substitute "Nature" for the God of nature, as if nature were a power in itself and apart from God, immanent in all nature, the present and efficient energy in all her manifold operations. Very fittingly, thus, do we find here again (ver. 25) the sanction affixed to this law, "I am the Lord your God!" Jehovah, your God who redeemed you, who therefore am worthy of all thanksgiving and praise! Jehovah, your God in covenant, who gives the fruitful seasons, filling your hearts with joy and gladness! Jehovah, your God, who as the Lord of Nature, and the Power in nature, am abundantly able to fulfil the promise affixed to this command!