"An earnest, prayerful study of the Sermon on the Mount will prepare us to proclaim the truth, to give to others the light we have received. We are first to take heed to ourselves, receiving with humble hearts the principles of truth and working them out in perfect obedience. This will bring joy and peace. Thus we eat the flesh and drink the blood of the Son of God, and we grow strong in His strength. Our lives are assimilated to His life. Our spirit, our inclinations, our habits, are conformed to the will of Him of whom God declared: “This is My beloved Son, in whom I am well pleased.” Matthew 3:17 . 7T 270.1"
"And lo a voice from heaven, saying, This is my beloved Son, in whom I am well pleased."
Ellen White directly references Matthew 3:17 in this passage.