John Trapp on Isaiah 8:20

Ver. 20. To the Law and to the Teſtimonies] Lo this is the way, walk in it, for. the Commandement is a Lamp, and the Law is Light, Prov. 6.23. They have Moſes and the Prophets, Luke 16.29. theſe muſt be the men of our Counſel, Pſal. 119.24. even theſe lively and Life-giving Oracles, Act. 7.38. not dead Idols, or damned Necromancers.

There is no light in them] either of truth or of comfort. Good expreſſions ſuch kind of creatures may uſe, it may be: but Si magicae, Deus non vult tales: ſi piae, non per tales: their falſe lights ſerve but to light them into utter darkneſs. Happy was Oecolampadius (an excellent Commentatour upon this Prophet) who made good the ſplendour of his own Name, when (beſide the light he lent to the Law and Teſtimonies) he could lay his hand on his breaſt when he lay a dying of the plague, and ſay, Here's plenty of light got from the Scripture.