Then said Daniel unto the king, O king, live for ever.

Jamieson-Fausset-Brown Bible Commentary

21. Daniel might have indulged in anger at the king, but does not; his sole thought is, God's glory has been set forth in his deliverance.

Matthew Henry's Concise Commentary

6:18-24 The best way to have a good night, is to keep a good conscience. We are sure of what the king doubted, that the servants of the living God have a Master well able to protect them. See the power of God over the fiercest creatures, and believe his power to restrain the roaring lion that goeth about continually seeking to devour. Daniel was kept perfectly safe, because he believed in his God. Those who boldly and cheerfully trust in God to protect them in the way of duty, shall always find him a present help. Thus the righteous is delivered out of trouble, and the wicked cometh in his stead. The short triumph of the wicked will end in their ruin.