Isaiah 8:20

“To the law, and to the testimony, &c.] 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 (<430539>John 5:39) and particularly what is before said in this prophecy concerning himself, the same is meant as on (<230816>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:…”

“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…”

“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?…”

“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. Isaiah 8:21”

“8:20 God gave instructions and teachings through the law and through his prophets, such as Isaiah (see 8:16).”

“the law: Isa 8:16; Luk 10:26, Luk 16:29-31; Joh 5:39, Joh 5:46, Joh 5:47; Act 17:11; Gal. 3:8-29; Gal 4:21, Gal 4:22; Ti2 3:15-17; Pe2 1:19 it is: Isa 30:8-11; Psa 19:7, Psa 19:8, Psa 119:130; Jer 8:9; Mic 3:6; Mat 6:23, Mat 22:29; Mar 7:7-9; Rom 1:22; Pe2 1:9 light: Heb. morning, Pro 4:18; Hos 6:3; Mal 4:2; Pe2 1:19 Isaiah 8:21”

“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, Isa 8:17), takes the form of a watchword in time of battle ( Jdg 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 Psa 131:2, "Surely they say such words as have no dawn in them") has, at any rate, all…”