Albert Barnes Commentary Daniel 6:20

"And when he came near unto the den to Daniel, he cried with a lamentable voice; the king spake and said to Daniel, O Daniel, servant of the living God, is thy God, whom thou servest continually, able to deliver thee from the lions?" — Daniel 6:20 (ASV)

He cried with a lamentable voice - A voice full of anxious concern. Literally, “a voice of grief.” Such a cry would be natural on such an occasion.

O Daniel, servant of the living God - The God who has life; who imparts life; and who can preserve life. This was the title, probably, which he had heard Daniel use in regard to God, and it is one which he would naturally use on such an occasion as this; feeling that the question of life was entirely in his hands.

Whom thou servest continually - At all times, and in all circumstances: as a captive in a distant land; in places of honor and power; when surrounded by the great who worship other gods; and when threatened with death for your devotion to the service of God. This had been the character of Daniel, and it was natural to refer to it now.