"what it has been proclaimed to be. Not all in regard to this matter is yet understood, nor will it be understood until the unrolling of the scroll; but a most solemn work is to be accomplished in our world. The Lord's command to His servants is: “Cry aloud, spare not, lift up thy voice like a trumpet, and show My people their transgression, and the house of Jacob their sins.” Isaiah 58:1 . 6T 17.1"
"Cry aloud, spare not, lift up thy voice like a trumpet, and shew my people their transgression, and the house of Jacob their sins."
Ellen White directly references Isaiah 58:1 in this passage.
"***** The three angels of Revelation 14 are represented as flying in the midst of heaven, symbolizing the work of those who proclaim the first, second, and third angels’ messages. All are linked together. The evidences of the abiding, everliving truth of these grand messages, that mean so much to the church, that have awakened such intense opposition from the religious world, are not extinct. Satan is constantly seeking to cast a shadow about these messages, so that the people of God shall not clearly discern their import, their time and place; but they live and are to exert their power upon our religious experience while time shall last. 6T 17.4"
"And I saw another angel fly in the midst of heaven, having the everlasting gospel to preach unto them that dwell on the earth, and to every nation, and kindred, and tongue, and people,"
The EGW passage explicitly refers to the three angels of Revelation 14 and their messages, directly alluding to the biblical text. The connection is undeniable and central to the passage's meaning.