And a stone was brought, and laid upon the mouth of the den; and the king sealed it with his own signet, and with the signet of his lords; that the purpose might not be changed concerning Daniel.
And a stone was brought ... and the king sealed it with his own signet - typical of Christ's entombment under a seal (Matthew 27:66). divinely ordered, that the deliverance might be the more striking.
With his own signet, and with the signet of his lords - the concurrence of the lords was required for making laws. In this respect kingly power had fallen since it was in Nebuchadnezzar's hands. The Median king is a puppet in his lords' hands; they take the security of their own seals, as well as his, that he should not release Daniel. The king's seal guaranteed Daniel from being killed by them, should he escape the lions.