"Royal Honor to Daniel What great honor is shown to Daniel by the Majesty of heaven! He comforts His trembling servant and assures him that his prayer has been heard in heaven. In answer to that fervent petition the angel Gabriel was sent to affect the heart of the Persian king. The monarch had resisted the impressions of the Spirit of God during the three weeks while Daniel was fasting and praying, but heaven's Prince, the Archangel, Michael, was sent to turn the heart of the stubborn king to take some decided action to answer the prayer of Daniel. SL 51"
"Then said he unto me, Fear not, Daniel: for from the first day that thou didst set thine heart to understand, and to chasten thyself before thy God, thy words were heard, and I am come for thy words."
The EGW passage directly refers to the events described in Daniel 10:12, including the angel Gabriel being sent in response to Daniel's prayer and the impact on the Persian king. It's a clear and direct allusion.
"“And when he had spoken such words unto me, I set my face toward the ground, and I became dumb. And, behold, one like the similitude of the sons of men touched my lips.... And said, O man greatly beloved, fear not: peace be unto thee, be strong, yea, be strong. And when he had spoken unto me, I was strengthened, and said, Let my Lord speak; for thou hast strengthened me” ( verses 15-19 ). So great was the divine glory revealed to Daniel that he could not endure the sight. Then the messenger of heaven veiled the brightness of his presence and appeared to the prophet as “one like the similitude of the sons of men” ( verse 16 ). By his divine power he strengthened this man of integrity and of faith, to hear the message sent to him from God. SL 51.3"
"And said, O man greatly beloved, fear not: peace be unto thee, be strong, yea, be strong. And when he had spoken unto me, I was strengthened, and said, Let my lord speak; for thou hast strengthened me."
The EGW passage quotes directly from Daniel 10:19 and references other verses in the same chapter, making it a clear and explicit allusion.