Jamieson, Fausset and Brown on Daniel 10:12

12. Fear not--Be not affrighted at my presence.

didst set thine heart to understand--what shall come to pass to thy people at the last times (compare Da 10:14).

chasten thyself--(Da 10:2, 3).

thy words were heard--(Ac 10:4). Prayer is heard at once in heaven, though the sensible answer may seem to be delayed. God's messenger was detained on the way (Da 10:13) by the opposition of the powers of darkness. If in our prayers amidst long protracted sorrows we believed God's angel is on his way to us, what consolation it would give us!

for thy words--because of thy prayers.