And the vision of the evening and the morning which was told is true: wherefore shut thou up the vision; for it shall be for many days.
The angel again confirms the assertion that no part of this vision was shewn to the Prophet in vain, because not even the slightest portion of it should fail of its effect. The necessity of this method of confirming our faith is notorious, because, although the events may be well known to us, yet we cannot acquiesce in God’s word, unless he should testify so...
Daniel sought understanding and did not seek in vain. Those who truly know God's things must desire to know more of them. When Gabriel approached, Daniel fell in fear and then into deep sleep, not from carelessness but from the weight of such abundance of revelations.
AI summary
Commenting on Daniel 8:15-27
And the vision of the evening and the morning which was told is true,.... That is, of the 2300 evenings and mornings, or natural days; unto which time the daily sacrifice was to cease, and the sanctuary and host trodden under foot; and then the sanctuary would be cleansed.