The matter — i.e., 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. (Comp. Luke 2:19.)
Related Commentaries of Daniel 7:28
Daniel 7:28
28 Hitherto is the end of the matter. As for me Daniel, my cogitations much troubled me, and my countenance changed in me: but I kept the matter in my heart.