Over the ephod was the breastplate, the most sacred of the priestly vestments. This was of the same material as the ephod. It was in the form of a square, measuring a span, and was suspended from the shoulders by a cord of blue from golden rings. The border was formed of a variety of precious stones, the same that form the twelve foundations of the City of God. Within the border were twelve stones set in gold, arranged in rows of four, and, like those in the shoulder pieces, engraved with the names of the tribes. The Lord's direction was, “Aaron shall bear the names of the children of Israel in the breastplate of judgment upon his heart, when he goeth in unto the holy place, for a memorial before the Lord continually.” Exodus 28:29 . So Christ, the great High Priest, pleading His blood before the Father in the sinner's behalf, bears upon His heart the name of every repentant, believing soul. Says the psalmist, “I am poor and needy; yet the Lord thinketh upon me.” Psalm 40:17 . PP 351.1…
"And Aaron shall bear the names of the children of Israel in the breastplate of judgment upon his heart, when he goeth in unto the holy place, for a memorial before the Lord continually."
EGW directly quotes Exodus 28:29 and then uses it as a basis for a spiritual analogy regarding Christ. It's a clear and direct connection.
"But I am poor and needy; yet the Lord thinketh upon me: thou art my help and my deliverer; make no tarrying, O my God."
Ellen White directly references Psalms 40:17 in this passage.
"At the right and left of the breastplate were two large stones of great brilliancy. These were known as the Urim and Thummim. By them the will of God was made known through the high priest. When questions were brought for decision before the Lord, a halo of light encircling the precious stone at the right was a token of the divine consent or approval, while a cloud shadowing the stone at the left was an evidence of denial or disapprobation. PP 351.2"
"And he shall stand before Eleazar the priest, who shall ask counsel for him after the judgment of Urim before the Lord: at his word shall they go out, and at his word they shall come in, both he, and all the children of Israel with him, even all the congregation."
EGW describes the function of the Urim and Thummim, drawing from the biblical mention of them and expanding on their supposed use in discerning God's will. While Numbers 27:21 doesn't describe the light and cloud, it does mention the Urim's role in seeking counsel from God.
"The miter of the high priest consisted of the white linen turban, having attached to it by a lace of blue, a gold plate bearing the inscription, “Holiness to Jehovah.” Everything connected with the apparel and deportment of the priests was to be such as to impress the beholder with a sense of the holiness of God, the sacredness of His worship, and the purity required of those who came into His presence. PP 351.3"
"And thou shalt make a plate of pure gold, and grave upon it, like the engravings of a signet, HOLINESS TO THE LORD."
EGW directly references and quotes Exodus 28:36 regarding the inscription on the high priest's miter.