"There the redeemed greet those who led them to the Saviour, and all unite in praising Him who died that human beings might have the life that measures with the life of God. The conflict is over. Tribulation and strife are at an end. Songs of victory fill all heaven as the ransomed ones take up the joyful strain, Worthy, worthy is the Lamb that was slain, and lives again, a triumphant conqueror. AA 602.1"
"Saying with a loud voice, Worthy is the Lamb that was slain to receive power, and riches, and wisdom, and strength, and honour, and glory, and blessing."
EGW directly quotes Revelation 5:12, although slightly paraphrased, and places it in a similar context of heavenly praise.
"“I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands; and cried with a loud voice, saying, Salvation to our God which sitteth upon the throne, and unto the Lamb.” Revelation 7:9, 10 . AA 602.2"
"After this I beheld, and, lo, a great multitude, which no man could number, of all nations, and kindreds, and people, and tongues, stood before the throne, and before the Lamb, clothed with white robes, and palms in their hands;"
The EGW passage directly quotes Revelation 7:9-10, making it a clear and explicit allusion.
"“These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb. Therefore are they before the throne of God, and serve Him day and night in His temple: and He that sitteth on the throne shall dwell among them. They shall hunger no more, neither thirst any more; neither shall the sun light on them, nor any heat. For the Lamb which is in the midst of the throne shall feed them, and shall lead them unto living fountains of waters: and God shall wipe away all tears from their eyes.” “And there shall be no more death, neither sorrow, nor crying, neither shall there be any more pain: for the former things are passed away.” Revelation 7:14-17 ; 21:4 . AA 602.3"
"And I said unto him, Sir, thou knowest. And he said to me, These are they which came out of great tribulation, and have washed their robes, and made them white in the blood of the Lamb. Therefore are they before the throne of God, and serve him day and night in his temple: and he that sitteth on the throne shall dwell among them. They shall hunger no more, neither thirst any more; neither shall the sun light on them, nor any heat. For the Lamb which is in the midst of the throne shall feed them, and shall lead them unto living fountains of waters: and God shall wipe away all tears from their eyes."
Ellen White directly references Revelation 7:14-17 in this passage.