"Then she told them how the matter had been presented to her in vision. Sometimes the multitudes in our world, to whom is sent the warning message from the word of God that Christ is soon coming, were presented to her as enveloped in mists and clouds and dense darkness, even as described by Isaiah, who wrote, “Behold, the darkness shall cover the earth, and gross darkness the people.” Isaiah 60:2 . LS 294.4"
"For, behold, the darkness shall cover the earth, and gross darkness the people: but the Lord shall arise upon thee, and his glory shall be seen upon thee."
Ellen White directly references Isaiah 60:2 in this passage.