"Moses was divinely commanded to make a serpent of brass resembling the living ones, and to elevate it among the people. To this, all who had been bitten were to look, and they would find relief. He did so, and the joyful news was sounded throughout the encampment that all who had been bitten might look upon the brazen serpent and live. Many had already died, and when Moses raised the serpent upon the pole, some would not believe that merely gazing upon that metallic image would heal them; these perished in their unbelief. Yet there were many who had faith in the provision which God had made. Fathers, mothers, brothers, and sisters were anxiously engaged in helping their suffering, dying friends to fix their languid eyes upon the serpent. If these, though faint and dying, could only once look, they were perfectly restored. PP 430.1"
"And the Lord said unto Moses, Make thee a fiery serpent, and set it upon a pole: and it shall come to pass, that every one that is bitten, when he looketh upon it, shall live."
The EGW passage directly references and expands upon the events described in Numbers 21:8.
"The people well knew that there was no power in the serpent of brass to cause such a change in those who looked upon it. The healing virtue was from God alone. In His wisdom He chose this way of displaying His power. By this simple means the people were made to realize that this affliction had been brought upon them by their sins. They were also assured that while obeying God they had no reason to fear, for He would preserve them. PP 430.2"
"Who forgiveth all thine iniquities; who healeth all thy diseases;"
Both passages connect healing with God's forgiveness and power. The EGW passage specifically mentions God's power being the source of healing, while the Psalm attributes both forgiveness and healing to God.
"The lifting up of the brazen serpent was to teach Israel an important lesson. They could not save themselves from the fatal effect of the poison in their wounds. God alone was able to heal them. Yet they were required to show their faith in the provision which He had made. They must look in order to live. It was their faith that was acceptable with God, and by looking upon the serpent their faith was shown. They knew that there was no virtue in the serpent itself, but it was a symbol of Christ; and the necessity of faith in His merits was thus presented to their minds. Heretofore many had brought their offerings to God, and had felt that in so doing they made ample atonement for their sins. They did not rely upon the Redeemer to come, of whom these offerings were only a type. The Lord would now teach them that their sacrifices, in themselves, had no more power or virtue than the serpent of brass, but were, like that, to lead their minds to Christ, the great sin offering. PP 430.3"
"And Moses made a serpent of brass, and put it upon a pole, and it came to pass, that if a serpent had bitten any man, when he beheld the serpent of brass, he lived."
EGW directly references and interprets the event described in Numbers 21:9, explaining its symbolic meaning.
"And as Moses lifted up the serpent in the wilderness, even so must the Son of man be lifted up:"
EGW directly references and interprets the event described in John 3:14, drawing a parallel between the lifting up of the serpent and the lifting up of Christ.
"And the Lord said unto Moses, Make thee a fiery serpent, and set it upon a pole: and it shall come to pass, that every one that is bitten, when he looketh upon it, shall live."
The EGW passage is a clear explanation and commentary on the event described in Numbers 21:8. It directly references the making and looking upon the brazen serpent.