Daniel 6:8-9

Under Persian law, the king was bound by the authority of a royal edict (Daniel 6:8; Daniel 6:12; Daniel 6:15; cf. Esther 1:19; Esther 8:8). This made his power less than it was under an absolute dictator such as Nebuchadnezzar (cf. Daniel 2:39).

"The action of Darius was both foolish and wicked. What led him to yield to the request of the ministers can only be conjectured, but probably he was greatly influenced by the claim of deity which many of the Persian kings made." [Note: Young, p. 134.]