Isa 8:20 (NIV): What does this means to Isaiah and for us today?

C Mc

Isa 8:20 (NIV): "To the law and to the testimony!" This is a verse often read but seldom understood. Although the Book of Isaiah was written in "the year King Uzziah died" (Isa 6:1), the prophet was young. The year was 740 B.C. when King Ahaz ruled (735-716 B.C.). In light of this, is the verse relevant to the serious Bible student today? CM