Commentaries:
The Bible clearly establishes that there is an angelic host to whom responsibilities and authority have been delegated by God. Gabriel came because of Daniel's appeal; he responded to Daniel's prayer. He came to Daniel's aid, but he was delayed from arriving immediately because He met resistance from another great being. Eventually, he had to receive help from a third great being named Michael, identified as "your prince." He is not Daniel's prince necessarily, but Israel's prince. We see an angelic being whose authority is over (or whose responsibility is to God in behalf of) the children of Israel.
John W. Ritenbaugh
Image and Likeness of God (Part Five)
Other Forerunner Commentary entries containing Daniel 10:20:
Luke 2:25
Luke 2:30-32
Luke 2:36-38
Revelation 12:7-9