After Darius signed a decree which said that anyone praying to any god but Darius should be thrown into the Lion's den, Daniel goes and prays anyway.
Daniel 6:10-11 ESV When Daniel knew that the document had been signed, he went to his house where he had windows in his upper chamber open toward Jerusalem. He got down on his knees three times a day and prayed and gave thanks before his God, as he had done previously. Then these men came by agreement and found Daniel making petition and plea before his God.
The author seems to go to great effort to show that Daniel didn't care about being caught, and that he may have even been encouraging it. Why else would the author state that Daniel knew the decree had been signed and that he went to a room that had windows opened towards Jerusalem, apparently to pray towards it.
What was the big deal about praying towards Jerusalem, and why was it so important that Daniel would be willing to die for it?
He could have prayed silently, or towards Jerusalem with the windows closed, or any other combination of non-law breaking things.
Daniel had been a fantastic rule follower up until that point, and he had proved himself to be smart to enough to work his way around the rules, and he certainly had the power and authority to do what he wanted. He seems to draw some sort of line here and state "I would rather die than pray in any way other than towards Jerusalem with the window open." Why?
To prevent this question from being opinion based I want to know what popular Christendom has had to say about this. Sole biblical basis is preferred.