From the first day. — The meaning appears to be that this vision was vouchsafed to him in consequence of his prayer to understand what would befal his people in the future. The prayer was heard from the first day that he offered it, but it had been impossible for him to realise the answer before the present time, for reasons mentioned in the next verse.
Related Commentaries of Daniel 10:12
Daniel 10:12
12 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.