'Sealed It' in the Bible

He wrote in the name of King Ahasuerus, and sealed it with the king’s signet ring, and sent letters by couriers on horses, riding on steeds sired by the royal stud.

A stone was brought and laid over the mouth of the den; and the king sealed it with his own signet ring and with the signet rings of his nobles, so that nothing would be changed in regard to Daniel.

and he threw him into the abyss, and shut it and sealed it over him, so that he would not deceive the nations any longer, until the thousand years were completed; after these things he must be released for a short time.