"Balaam confessed that he came with the purpose of cursing Israel, but the words he uttered were directly contrary to the sentiments of his heart. He was constrained to pronounce blessings, while his soul was filled with curses. PP 447.1"
"How shall I curse, whom God hath not cursed? or how shall I defy, whom the Lord hath not defied?"
The EGW passage describes Balaam's internal conflict and the external blessings he was forced to pronounce, which directly relates to the question posed in Numbers 23:8 about the impossibility of cursing whom God has not cursed. While not a direct quote, it amplifies the situation.
"Which have forsaken the right way, and are gone astray, following the way of Balaam the son of Bosor, who loved the wages of unrighteousness;"
The EGW passage describes Balaam's actions and motivations, which are condemned in 2 Peter 2:15. The connection is that both passages discuss Balaam's character and his pursuit of personal gain over righteousness.
"saw the vast extent and perfect arrangement of their camp, everything bearing the marks of thorough discipline and order. He was shown the favor with which God regarded Israel, and their distinctive character as His chosen people. They were not to stand upon a level with other nations, but to be exalted above them all. “The people shall dwell alone, and shall not be reckoned among the nations.” At the time when these words were spoken the Israelites had no permanent settlement, and their peculiar character, their manners and customs, were not familiar to Balaam. But how strikingly was this prophecy fulfilled in the after-history of Israel! Through all the years of their captivity, through all the ages since they were dispersed among the nations, they have remained a distinct people. So the people of God—the true Israel—though scattered throughout all nations, are on earth but sojourners, whose citizenship is in heaven. PP 447.2"
"For from the top of the rocks I see him, and from the hills I behold him: lo, the people shall dwell alone, and shall not be reckoned among the nations."
EGW directly quotes Numbers 23:9 and elaborates on its meaning in the context of Israel's distinctiveness and God's chosen people. The connection is undeniable.
"Not only was Balaam shown the history of the Hebrew people as a nation, but he beheld the increase and prosperity of the true Israel of God to the close of time. He saw the special favor of the Most High attending those who love and fear Him . He saw them supported by His arm as they enter the dark valley of the shadow of death. And he beheld them coming forth from their graves, crowned with glory, honor, and immortality. He saw the redeemed rejoicing in the unfading glories of the earth made new. Gazing upon the scene, he exclaimed, “Who can count the dust of Jacob, and the number of the fourth part of Israel?” And as he saw the crown of glory on every brow, the joy beaming from every countenance, and looked forward to that endless life of unalloyed happiness, he uttered the solemn prayer, “Let me die the death of the righteous, and let my last end be like his!” PP 447.3"
"Yea, though I walk through the valley of the shadow of death, I will fear no evil: for thou art with me; thy rod and thy staff they comfort me."
EGW's description of the righteous being supported through the valley of the shadow of death and ultimately resurrected with glory echoes the sentiment and imagery of Psalm 23:4. While not a direct quote, the thematic resonance is strong.