"John saw the mercy, the tenderness, and the love of God blending with His holiness, justice, and power. He saw sinners finding a Father in Him of whom their sins had made them afraid. And looking beyond the culmination of the great conflict, he beheld upon Zion “them that had gotten the victory ... stand on the sea of glass, having the harps of God,” and singing “the song of Moses” and the Lamb. Revelation 15:2, 3 . AA 589.1"
"And I saw as it were a sea of glass mingled with fire: and them that had gotten the victory over the beast, and over his image, and over his mark, and over the number of his name, stand on the sea of glass, having the harps of God."
EGW directly quotes Revelation 15:2.
"The Saviour is presented before John under the symbols of “the Lion of the tribe of Judah” and of “a Lamb as it had been slain.” Revelation 5:5, 6 . These symbols represent the union of omnipotent power and self- sacrificing love. The Lion of Judah, so terrible to the rejectors of His grace, will be the Lamb of God to the obedient and faithful. The pillar of fire that speaks terror and wrath to the transgressor of God's law is a token of light and mercy and deliverance to those who have kept His commandments. The arm strong to smite the rebellious will be strong to deliver the loyal. Everyone who is faithful will be saved. “He shall send His angels with a great sound of a trumpet, and they shall gather together His elect from the four winds, from one end of heaven to the other.” Matthew 24:31 . AA 589.2"
"And he shall send his angels with a great sound of a trumpet, and they shall gather together his elect from the four winds, from one end of heaven to the other."
Ellen White directly references Matthew 24:31 in this passage.