Daniel 6:14

Overview - Daniel 6
Daniel is made chief of the presidents.
They, conspiring against him, obtain an idolatrous decree.
10 Daniel, accused of the breach thereof, is cast into the lion's den.
18 Daniel is saved;
24 his adversaries devoured;
25 and God magnified by a decree.
Treasury of Scripture Knowledge

Daniel 6:14  (King James Version)
Then the king, when he heard these words, was sore displeased with himself, and set his heart on Daniel to deliver him: and he laboured till the going down of the sun to deliver him.

was sore
The king now clearly perceived for what purpose the decree had been solicited; and was exceedingly displeased with himself that he had suffered himself to be so deluded.
3:13 Matthew 27:17-24 ; Mark 6:26 ; Luke 23:13-21 ; John 19:7-12

and he
He strove during the whole day, by every means, to evade or annul the edict; but the foolish constitution of his government (exactly the reverse of the happy rule for the conduct of our gracious monarch) did not allow them to pardon any person who had broken one of their decrees, however arbitrary and unreasonable.
2 Samuel 3:28 2 Samuel 3:29