"Instruct the Church in Missionary Work “Watchman, what of the night?” Isaiah 21:11 . Are the watchmen of whom this demand is made able to give the trumpet a certain sound? Are the shepherds faithfully caring for the flock as those who must give an account? Are the ministers of God watching for souls, realizing that those under their care are the purchase of the blood of Christ? A great work is to be done in the world, and what efforts are we making for its accomplishment? The people have had too much sermonizing; but have they been taught how to labor for those for whom Christ died? Has a line of labor been devised and placed before them in such a way that each has seen the necessity of taking part in the work? 6T 431"
"The burden of Dumah. He calleth to me out of Seir, Watchman, what of the night? Watchman, what of the night?"
Ellen White directly references Isaiah 21:11 in this passage.