Isaiah 8:20

Then you must recall the Lord’s instructions and the prophetic testimony of what would happen. ¹  Certainly they say such things because their minds are spiritually darkened. ² 

Ps 19:7,8; Ps 119:130; Pr 4:18; Isa 8:16; Isa 30:8-11; Jer 8:9; Ho 6:3; Mic 3:6; Mal 4:2; Mt 6:23; Mt 22:29; Mr 7:7-9; Lu 10:26; Lu 16:29-31; Joh 5:39,46,47; Ac 17:11; Ro 1:22; Ga 3:8-29; Ga 4:21,22; 2Ti 3:15-17; 2Pe 1:9; 2Pe 1:19

¹ tn Heb “to [the] instruction and to [the] testimony.” The words “then you must recall” are supplied in the translation for stylistic reasons. In the Hebrew text vv. 19-20a are one long sentence, reading literally, “When they say to you…, to the instruction and to the testimony.” On the identity of the “instruction” and “testimony” see the notes at v. 16.

² tn Heb “If they do not speak according to this word, [it is] because it has no light of dawn.” The literal translation suggests that “this word” refers to the instruction/testimony. However, it is likely that אִם־לֹא (’im-lo’) is asseverative here, as in 5:9. In this case “this word” refers to the quotation recorded in v. 19. For a discussion of the problem see J. N. Oswalt, Isaiah (NICOT), 230, n. 9. The singular pronoun in the second half of the verse is collective, referring back to the nation (see v. 19b).