"Together these two aged men and the younger one toiled up the mountain height. The heads of Moses and Aaron were white with the snows of sixscore winters. Their long and eventful lives had been marked with the deepest trials and the greatest honors that had ever fallen to the lot of man. They were men of great natural ability, and all their powers had been developed, exalted, and dignified by communion with the Infinite One. Their life had been spent in unselfish labor for God and their fellow men; their countenances gave evidence of great intellectual power, firmness and nobility of purpose, and strong affections. PP 425.2"
"And Moses stripped Aaron of his garments, and put them upon Eleazar his son; and Aaron died there in the top of the mount: and Moses and Eleazar came down from the mount."
Both passages describe Moses and Aaron on a mountain, leading to Aaron's death. EGW elaborates on the scene and their character, but the core event is present in both.
"the mountains of Edom was the path leading to the Promised Land—that land whose blessings Moses and Aaron were not to enjoy. No rebellious feelings found a place in their hearts, no expression of murmuring escaped their lips; yet a solemn sadness rested upon their countenances as they remembered what had debarred them from the inheritance of their fathers. PP 425.3"
"And the Lord spake unto Moses and Aaron, Because ye believed me not, to sanctify me in the eyes of the children of Israel, therefore ye shall not bring this congregation into the land which I have given them."
EGW directly refers to the reason Moses and Aaron were barred from the Promised Land, which is explicitly stated in Numbers 20:12. This is a clear and direct allusion.