NET
20 Then you must recall the Lord’s instructions and the prophetic testimony of what would happen. Certainly they say such things because their minds are spiritually darkened.
Darby
20 To the law and the testimony! If they speak not according to this word, for them there is no daybreak.
KJV
20 To the law and to the testimony: if they speak not according to this word, [it is] because [there is] no light in them.