Albert Barnes Commentary Micah 3:6

"Therefore it shall be night unto you, that ye shall have no vision; and it shall be dark unto you, that ye shall not divine; and the sun shall go down upon the prophets, and the day shall be black over them." — Micah 3:6 (ASV)

Therefore night shall be unto you, that ye shall not have a vision - In the presence of God’s extreme judgments, even deceivers are eventually still; silenced at last by the common misery, if not by awe. The false prophets had promised peace, light, brightness, prosperity; the night of trouble, anguish, darkness, fear, will come upon them. So they will no longer dare to speak in the Name of God, while He was, by His judgments, speaking the contrary in a way that all must hear.

They abused God’s gifts and long-suffering against Himself; they could misinterpret His long-suffering as favor, and they did so. Their visions of the future were only the reflections of the present and its continuation. They thought that because God was enduring, He was indifferent. Consequently, they took His government out of His hands and said that what He appeared to be now, He would always be.

They had no other light, no other foresight. Then, when the darkness of temporal calamity enveloped them, it shrouded in one common darkness of night all present brightness and all sight of the future.

Rup.: “After Caiaphas had in heart spoken falsehood and a prophecy of blood, although God overruled it to truth which he did not intend, all grace of prophecy departed (Matthew 11:13). The law and the prophets prophesied until John. “The Sun of Righteousness went down over them,” inwardly and outwardly, withdrawing the brightness of His Providence and the inward light of grace.”

So Christ Himself forewarned, Walk while ye have the light, lest darkness come upon you (John 12:35). And so it has remained ever since (2 Corinthians 3:15). The veil has been on their hearts. The light is in all the world, but they do not see it; it arose to lighten the Gentiles, but they still walk on in darkness.

As opposed to holiness, truth, knowledge, divine enlightening of the mind, and bright gladness, conversely darkness is falsehood, sin, error, blindness of soul, ignorance of divine things, and sorrow.

In all these ways, the Sun went down “over them,” so that the darkness weighed heavily upon them.

So too, the inventors of heresies pretend to see and to enter into the mysteries of Christ, yet they find darkness instead of light. They lose even what they think they see and fail even concerning the truth they seem most to hold. They will be in night and darkness, being cast into outer darkness (1 Corinthians 8:12); sinning against the brethren and wounding their weak conscience, those for whom Christ died.