Matthew 24:15 “So when you see standing in the holy place‘the abomination that causes desolation, spoken of through the prophet Daniel—let the reader understand—16 then let those who are in Judea flee to the mountains.
When The Lord referred to the prophet Daniel he was speaking to an audience that knew about Daniel and his times. And, very notably, this is the only place the Word is directly addressed to "the reader" -- That would be us. We must be an audience that knows about Daniel and his times.
The book of Daniel paints the picture of a man who was hugely gifted, extremely humble and clearly holy, which means "set apart for God." He was described by an angel as "you who are highly esteemed. " (Daniel 10:11). We find in the book Revelation and Daniel are a set that each explain, fore-shadow or amplify each other in God's revelation to Daniel and John about the end times. They fit together like primary puzzle pieces, with Jeremiah, Ezekiel, Isaiah and the Olivet Discourse filling in most blanks.
Daniel was given this revelation, this prophesy, in visions, dreams and directly by angels, including Gabriel. Just as John on the isle of Patmos, Daniel was given these revelations in a time of trial and exile.
Daniel received these dreams, visions and angelic visits while he was captive in Babylon during the worst catastrophe in Israel's experience. (At that time, anyway. There was more to come. It was the beginning of the "Age of the Gentiles.") Jerusalem and the temple had been destroyed by Babylonian army and the population marched into captivity in Babylon. Daniel was a boy, probably in his early teenage years, when his homeland and his people were devastated.
The first 3 chapters of the book introduce us to Daniel and his friends, selected from the best and brightest of Jewish male teenagers to be trained for the positions in the king's court. We meet Daniel and his friends, an begin to receive insight into their uncompromising righteousness in Capter 1:7-8 "Among those who were chosen were some from Judah: Daniel, Hananiah, Mishael and Azariah. The chief official gave them new names: to Daniel, the name Belteshazzar; to Hananiah, Shadrach; to Mishael, Meshach; and to Azariah, Abednego. But Daniel resolved not to defile himself with the royal food and wine, and he asked the chief official for permission not to defile himself this way.
Here is the video of the teaching on Daniel 1-3