Charles Ellicott Commentary Daniel 7:28

"Here is the end of the matter. As for me, Daniel, my thoughts much troubled me, and my countenance was changed in me: but I kept the matter in my heart." — Daniel 7:28 (ASV)

The matter — that is, the vision and the revelation.

In my heart. — Daniel suffers as in Daniel 7:15 and Daniel 10:8. However, he comforts himself by keeping in his heart the words of the angel spoken in Daniel 7:17. (Compare to Luke 2:19.)