God's witness for all later ages is his written word. Primarily it is his voice sounded out from Sinai in his holy law, comprehending all morality, written by his own finger on tables of stone. This law is a test of all words, all doctrines, all creeds, all teachings, all voices, which come after it. Are the teachings of any one in harmony with that word?—accept them; it is simply truth's witness to truth. Does a new prophet arise?—and does his teaching lead man away from that law?—Then it is false, follow it not. But are his words in harmony with God's voice?—Then it is God's word confirming God's word. So when Christ walked the earth he said that in the closing of the days of persecution in the Dark Ages the sun should be darkened. Nearly eighteen centuries rolled away, and May 19, 1780, the phenomenon occurred just when the Lord said it would. What was that obscuration of the sun?—It was God's word in the sky confirming God's word given through Matthew and Mark. The standard was the written prophetic word, and when the sun was darkened, God's word was written again. We know it was God's word, because it confirmed the written word. It was not the main witness of truth, but a concurring witness, warning the world, and confirming the hope of the people of God.