To the law ... - To the revelation which God has given. This is a solemn call of the prophet to try everything by the revealed will of God; see Isaiah 8:16.

If they speak not - If the necromancers - those that pretended to have contact with the dead.

According to this word - According to what God has revealed. By this standard all their pretended revelations were to be tried. By this standard all doctrines are still to be tried.

It is because - There has been a great variety of criticism upon this verse, but our translation expresses, probably, the true idea. The word rendered here 'because,' אשׁר 'ăsher, commonly denotes 'which;' but it seems here to be used in the sense of the Syriac? "Dolath," or the Greek ὅτι hoti.

No light - Margin, 'Morning.' Hebrew שׁחר shāchar. The word usually means the morning light; the mingled light and darkness of the aurora; daybreak. It is an emblem of advancing knowledge, and perhaps, also, of prosperity or happiness after calamity, as the break of day succeeds the dark night. The meaning here may be, 'If their teachings do not accord with the law and the testimony, it is proof that they are totally ignorant, without even the twilight of true knowledge; that it is total darkness with them.' Or it may mean, 'If they do not speak according to this word, then no dawn will arise, that is, no prosperity will smile upon this people.' - Gesenius. Lowth understands it of obscurity, darkness:

'If they speak not according to this word,

In which there is no obscurity.'

But there is no evidence that the word is ever used in this sense. Others suppose that the Arabic sense of the word is to be retained here, deception, or magic. 'If they speak not according to this oracle, in which there is no deception.' But the word is not used in this sense in the Hebrew. The meaning is, probably, this: 'The law of God is the standard by which all professed communications from the invisible world are to be tested. If the necromancers deliver a doctrine which is not sustained by that, and not in accordance with the prophetic communications, it shows that they are in utter ignorance. There is not even the glimmering of the morning twilight; all is total night, and error, and obscurity with them, and they are not to be followed.'

To the law and to the testimony "Unto the command, and unto the testimony" - "Is not תעודה teudah here the attested prophecy, Isaiah 8:1-4? and perhaps תורה torah the command, Isaiah 8:11-15? for it means sometimes a particular, and even a human, command; see Proverbs 6:20, and Proverbs 7:1, Proverbs 7:2, where it is ordered to be hid, that is, secretly kept." - Abp. Secker. So Deschamps, in his translation, or rather paraphrase, understands it: "Tenons nous a l'instrument authentique mis en depot par ordre du Seigneur," "Let us stick to the authentic instrument, laid up by the command of the Lord." If this be right, the sixteenth verse must be understood in the same manner.

Because there is no light in them "In which there is no obscurity" - שחר shachor, as an adjective, frequently signifies dark, obscure; and the noun שחר shachar signifies darkness, gloominess, Joel 2:2, if we may judge by the context: -

"A day of darkness and obscurity;

Of cloud, and of thick vapor;

As the gloom spread upon the mountains:

A people mighty and numerous."

Where the gloom, שחר shachar, seems to be the same with the cloud and thick vapor mentioned in the line preceding. See Lamentations 4:8, and Job 30:30. See this meaning of the word שחר shachar well supported in Christ. Muller. Sat. Observat. Philippians p. 53, Lugd. Bat. 1752. The morning seems to have been an idea wholly incongruous in the passage of Joel; and in this of Isaiah the words in which there is no morning (for so it ought to be rendered if שחר shachar in this place signifies, according to its usual sense, morning) seem to give no meaning at all. "It is because there is no light in them," says our translation. If there be any sense in these words, it is not the sense of the original; which cannot justly be so translated. Qui n'a rien d'obscur, "which has no obscurity." - Deschamps. The reading of the Septuagint and Syriac, שחד shochad, gift, affords no assistance towards the clearing up of any of this difficult place. R. D. Kimchi says this was the form of an oath: "By the law and by the testimony such and such things are so." Now if they had sworn this falsely, it is because there is no light, no illumination, שחר shachar, no scruple of conscience, in them.

To the law, and to the testimony,.... Kimchi takes this to be an oath, "by the law, and by the testimony", it is so and so; but Aben Ezra observes there is no instance of this kind in Scripture; it is a direction of Christ's to his disciples, to attend to the writings of Moses and the prophets, to search the Scriptures, as in John 5:39 and particularly what is before said in this prophecy concerning himself, the same is meant as on Isaiah 8:16.

if they speak not according to this word; this sure word of prophecy, to which men do well to take heed, as to a light shining in a dark place, it being the rule of faith and practice, a lamp to the feet, and a light to the path:

it is because there is no light in them; that is, in them that speak not according to it, meaning the Scribes and Pharisees; who, rejecting the written word, set up the traditions of the elders above it, and taught the people to walk according to them; and so were, as our Lord says, "blind leaders of the blind", Matthew 15:14 or the words may be read, "if not"; if they will not regard the Scriptures, and the evangelical doctrine in them, and the testimony they give concerning Christ; "let them speak according to this word"; or instruction, and counsel, they have from the Scribes and Pharisees: "in which there is no light" (b); but the darkness of ignorance, infidelity, superstition, and will worship; or "no morning"; but a night of Jewish darkness, even though the sun of righteousness was risen, and the dayspring from on high had visited the earth; yet they had received no light and knowledge from him, which was their condemnation, John 1:4, John 3:19 or thus, "to the law, and to the testimony, though they may say after this manner, there is no light in it" (c); in the law and testimony, preferring the traditions, decisions, and determinations of their doctors above it. Noldhius (d) renders the words thus, "seeing they speak not according to this word, certainly they shall have no morning"; that is, seeing the seducers and false teachers, in the preceding verse Isaiah 8:19, speak not according to the word of God, and testimony of Jesus, they shall have no morning of light and joy, of grace and comfort, or any spiritual felicity; Christ will be no morning to them, but they will continue in their dark, benighted, and miserable condition, described in the following verse.

(b) "sin minus, dicant secundum verbum istud, cui mon est aurora", Piscator. So Sanctius. (c) "Licet ipsi dicent, in verbis legis, nihil lucis esse", Oleaster in Bootius. (d) Ebr. Part. Concord. p. 374. No. 1302.

In opposition to such a falling away to wretched superstition, the watchword of the prophet and his supporters is this. "To the teaching of God (thorah, Gotteslehre), and to the testimony! If they do not accord with this word, they are a people for whom no morning dawns." The summons, "to the teaching and to the testimony" (namely, to those which Jehovah gave through His prophet, Isaiah 8:17), takes the form of a watchword in time of battle (Judges 7:18). With this construction the following אם־לא (which Knobel understands interrogatively, "Should not they speak so, who, etc.?" and Luzzatto as an oath, as in Psalm 131:2, "Surely they say such words as have no dawn in them") has, at any rate, all the presumption of a conditional signification. Whoever had not this watchword would be regarded as the enemy of Jehovah, and suffer the fate of such a man. This is, to all appearance, the meaning of the apodosis שׁהר אין־לו אשׁר. Luther has given the meaning correctly, "If they do not say this, they will not have the morning dawn;" or, according to his earlier and equally good rendering, "They shall never overtake the morning light," literally, "They are those to whom no dawn arises." The use of the plural in the hypothetical protasis, and the singular in the apodosis, is an intentional and significant change. All the several individuals who did not adhere to the revelation made by Jehovah through His prophet, formed one corrupt mass, which would remain in hopeless darkness. אשׁר is used in the same sense as in Isaiah 5:28 and 2 Samuel 2:4, and possibly also as in 1 Samuel 15:20, instead of the more usual כּי, when used in the affirmative sense which springs in both particles out of the confirmative (namque and quoniam): Truly they have no morning dawn to expect.

(Note: Strangely enough, Isaiah 8:19 and Isaiah 8:20 are described in Lev. Rabba, ch. xv, as words of the prophet Hosea incorporated in the book of Isaiah.)

To the {y} law and to the testimony: if they speak not according to this word, it is because there is no {z} light in them.

(y) Seek remedy in the word of God, where his will is declared.

(z) They have no knowledge but are blind leaders of the blind.

8:20 To the law - Let this dispute between you and them be determined by God's word, which is here and in many other places called the law, to signify their obligation to believe and obey it; and the testimony, because it is a witness between God and man, of God's will, and of man's duty. They - Your antagonists. No light - This proceeds from the darkness of their minds, they are blind, and cannot see.

no...: Heb. no morning

20. To the law, &c.-the revelation of God by His prophet (Isa 8:16), to which he directs them to refer those who would advise necromancy.

if they speak not . it is because-English Version understands "they" as the necromancers. But the Hebrew rendered "because" is not this but "who"; and "if not," ought rather to be "shall they not"; or, truly they shall speak according to this word, who have no morning light (so the Hebrew, that is, prosperity after the night of sorrows) dawning on them [Maurer and G. V. Smith]. They who are in the dark night of trial, without a dawn of hope, shall surely say so, Do not seek, as we did, to necromancy, but to the law," &c. The law perhaps includes here the law of Moses, which was the "Magna Charta" on which prophetism commented [Kitto].

8:17-22 The prophet foresaw that the Lord would hide his face; but he would look for his return in favour to them again. Though not miraculous signs, the children's names were memorials from God, suited to excite attention. The unbelieving Jews were prone to seek counsel in difficulties, from diviners of different descriptions, whose foolish and sinful ceremonies are alluded to. Would we know how we may seek to our God, and come to the knowledge of his mind? To the law and to the testimony; for there you will see what is good, and what the Lord requires. We must speak of the things of God in the words which the Holy Ghost teaches, and be ruled by them. To those that seek to familiar spirits, and regard not God's law and testimony, there shall be horror and misery. Those that go away from God, go out of the way of all good; for fretfulness is a sin that is its own punishment. They shall despair, and see no way of relief, when they curse God. And their fears will represent every thing as frightful. Those that shut their eyes against the light of God's word, will justly be left to darkness. All the miseries that ever were felt or witnessed on earth, are as nothing, compared with what will overwhelm those who leave the words of Christ, to follow delusions.