Deuteronomy 17:8

8If there arise a matter too hard for thee. The principal office of the priests is here described under a single head, viz., that they should declare what was right in doubtful and obscure matters out of the Law of God; for although God seems only to refer to civil controversies, yet there is no doubt but that by synecdoche He appoints them to be interpreters of the doctrine of the Law. That their authority might be more reverenced in general, He commands the people to acquiesce in their judgment even on the most disagreeable points: for if their sentence is to be submitted to where a man’s life is in question, or when any disputes are to be settled, much more is all exception taken away with respect to God’s worship and spiritual doctrine. I confess that the priests are not the sole judges here appointed, but that others of the people are associated with them as colleagues, yet the dignity of the priesthood is especially exalted. The opinion which some hold, that the high priest alone is intended by the word judge, is easily refuted; because Moses distinctly enumerates the priests, the Levites, and the judge. But it is probable that there is by enallage a change of number in it; for it appears from the sacred history that several were appointed, where Jehoshaphat is related to have chosen “of the Levites, and of the priests, and of the chief of the fathers of Israel” to preside at Jerusalem in judgment. (2 Chronicles 19:8.) Assuredly the pious king would have been unwilling to depart in the very least degree from the rule of the Law, and his zeal is praised by the Holy Spirit Himself: but this was the arrangement made, as appears a little further on, that the high priest held the primacy “in matters of the Lord,” and the king’s governor attended to civil causes and earthly affairs. And thus again is confirmed what I have lately adverted to, i.e., that the office of teaching was entrusted to the priests, that they might solve any difficult questions, which is also supported by the words of Jehoshaphat, when he says, “And what cause soever shall come to you of your brethren — between blood and blood, between law and commandment, statutes and judgments, ye shall even warn them that they trespass not against the Lord.” (2 Chronicles 19:10.)

Certainly, as the cognisance of capital crimes properly belonged to judges of the other tribes, so determinations as to precepts and statutes, and the interpretation of the whole Law, was the peculiar province of the priests; nor can we doubt but that the words of Malachi, (Malachi 2:7,) “the priests’ lips should keep knowledge, and they should seek the law at his mouth: for he is the messenger of the Lord of hosts,” were taken from this passage. Now, to come to the sum of this, God appoints the seat of judgment to be at the sanctuary; for, although in the first verse He seems to nominate the priests and judges indiscriminately to the decision of earthly quarrels, yet in the fourth verse from this He sufficiently shews that another province is committed to the priests, i.e., to keep the people in sound and pure doctrine, and to expound what is right — in a word, to be the teachers of the Church. But, although the people were to assent to whatever they should decide, so that it would be sinful for them to decline from it to the right hand or the left, yet a tyrannical power was not thus put into their hands, as if, when they had arbitrarily changed light into darkness, their perverted decisions were to be deemed oracular. Their interpretation was to be received without appeal; yet, on the other hand, this rule was prescribed to them, that they should speak as from the mouth of God. It is true that the word here used is, תורה, (206) thorah; which, although it means teaching, yet undoubtedly signifies that teaching which is comprised in the Law, nay, it is equivalent to the word law. And of this Jehoshaphat is a faithful interpreter, when he enumerates the divisions, of which Scripture everywhere shews the Law of Moses to consist. Although פי, phi, taken metaphorically, is equivalent in Hebrew to discourse, yet it here emphatically expresses the sentence which shall be taken from the pure teaching of the Law. The children of Israel, therefore, are commanded to do what the priests shall have taught them; but how? according to the sentence taken from the Law. Nor can it be doubted but that God at the same time furnished those, whom He desired to exalt to such a high dignity, with the spirit of understanding and rectitude, that they might not deliver any improper sentence. And this also is conveyed by the promise, “They shall shew thee the sentence of judgment:” since it would have been absurd that the people should have obeyed God in vain, and to their own destruction. Since now one sole Priest, who is also our Master, even Christ, is set over us, wo be unto us if we do not simply submit ourselves to His word, and are not ready to obey Him, with all the modesty and teachableness that becomes us.