Albert Barnes Commentary Daniel 6:19

"Then the king arose very early in the morning, and went in haste unto the den of lions." — Daniel 6:19 (ASV)

Then the king arose very early in the morning ... – No one can doubt the probability of what is said here, if the previous account is true. His deep anxiety; his wakeful night; the remorse which he endured, and his hope that Daniel would, after all, be preserved, all would prompt an early visit to the place of his confinement, and his earnestness in ascertaining whether he was still alive.