Daniel 6:8
Now, O king, establish the decree, and sign the writing, that it be not changed, according to the law of the Medes and Persians, which altereth not.
Cross-reference
In Daniel 6:24, the accusers are punished by the same irreversible decree, showing its consequences.
In Daniel 6:15, the irreversible decree from 6:8 is invoked to prevent the king from saving Daniel — the law traps even its maker.
Esther 1:19 shows the same irrevocable Persian law used to depose Queen Vashti — a parallel legal custom.
In Esther 3:12, the same Persian legal process of writing and sealing an irreversible decree is used, confirming the practice.
In Esther 8:10, a new decree is sealed to counter the previous one, contrasting with Daniel's claim that the decree cannot be changed.
In Isaiah 10:1, a woe is pronounced on those who decree unrighteous decrees, directly condemning the decree in Daniel.
Esther 8:8 explicitly states that a royal decree sealed with the king's ring cannot be revoked — the exact same law as in Daniel.
Matthew 24:35 contrasts the temporary unchangeability of human law with the eternal permanence of Jesus' words.