"The youth in this school of training were not only to be admitted to the royal palace, but it was provided that they should eat of the meat and drink of the wine which came from the king's table. In all this the king considered that he was not only bestowing great honor upon them, but securing for them the best physical and mental development that could be attained. SL 19.1"
"And the king spake unto Ashpenaz the master of his eunuchs, that he should bring certain of the children of Israel, and of the king’s seed, and of the princes; Children in whom was no blemish, but well favoured, and skilful in all wisdom, and cunning in knowledge, and understanding science, and such as had ability in them to stand in the king’s palace, and whom they might teach the learning and the tongue of the Chaldeans. And the king appointed them a daily provision of the king’s meat, and of the wine which he drank: so nourishing them three years, that at the end thereof they might stand before the king."
The EGW passage directly references and elaborates on the events described in Daniel 1:3-5, specifically the king's provision of food and wine for the Israelite youths.
"Daniel did not long hesitate. He decided to stand firm in his integrity, let the result be what it might. He “purposed in his heart that he would not defile himself with the portion of the king's meat, nor with the wine which he drank” ( Daniel 1:8 ). SL 19.3"
"But Daniel purposed in his heart that he would not defile himself with the portion of the king’s meat, nor with the wine which he drank: therefore he requested of the prince of the eunuchs that he might not defile himself."
Ellen White directly references Daniel 1:8 in this passage.