Dan 8:14 And he said unto me,
Unto two thousand and three hundred days; then shall the sanctuary be cleansed.
Dan 8:15 And it came to pass, when I, even I Daniel, had seen the vision, and sought for the meaning, then, behold, there stood before me as the appearance of a man.
Daniel was given a vision and couldn't understand it. Notice the 2300 days. Then the Angel Gabriel came to help Daniel, but he still didn't get it. "make this man to understand the vision."
Dan 8:26 And the vision of the evening and the morning which was told is true: wherefore shut thou up the vision; for it shall be for many days.
Dan 8:27 And I Daniel fainted, and was sick certain days; afterward I rose up, and did the king's business; and I was astonished at the vision,
but none understood it.
So Daniel is sick and can't understand it.... But then Gabriel comes back....
Dan 9:21 Yea, whiles I was speaking in prayer, even the man Gabriel, whom I had seen
in the vision at the beginning, being caused to fly swiftly, touched me about the time of the evening oblation.
Dan 9:22 And he informed me, and talked with me, and said, O Daniel, I am now come forth to give thee skill and understanding.
Dan 9:23 At the beginning of thy supplications the commandment came forth, and
I am come to shew thee; for thou art greatly beloved: therefore understand the matter, and consider the vision.
This needs to be connected to the 2300 day vision in chapter 8.
Dan 9:24 Seventy weeks are determined upon thy people and upon thy holy city,
70 weeks out of the 2300 days were given to Israel to get things right.
Same starting point for both.