"As Jesus died on Calvary, He cried, “It is finished,” and the veil of the temple was rent in twain, from the top to the bottom. This was to show that the services of the earthly sanctuary were forever finished, and that God would no more meet with the priests in their earthly temple, to accept their sacrifices. The blood of Jesus was then shed, which was to be offered by Himself in the heavenly sanctuary. As the priest entered the most holy once a year to cleanse the earthly sanctuary, so Jesus entered the most holy of the heavenly, at the end of the 2300 days of Daniel 8 , in 1844, to make a final atonement for all who could be benefited by His mediation, and thus to cleanse the sanctuary. EW 253.1"
"And, behold, the veil of the temple was rent in twain from the top to the bottom; and the earth did quake, and the rocks rent;"
EGW directly references the rending of the veil in the temple at Jesus' death, as described in Matthew 27:51. She uses this event as a symbolic representation of the end of the earthly sanctuary's services.
"Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place, having obtained eternal redemption for us."
The EGW passage directly echoes the concept of Jesus entering the heavenly sanctuary with his own blood, as described in Hebrews 9:12. It expands on the verse by connecting it to the cleansing of the sanctuary and the final atonement.