'Observances' in the Bible

The command of Esther established these customs for Purim, and it was written in the book [of the royal archives].

“How can you say, ‘We are wise,And the law of the Lord is with us [and we are learned in its language and teachings]’?Behold, [the truth is that] the lying pen of the scribesHas made the law into a lie [a mere code of ceremonial observances].

how much more will the blood of Christ, who through the eternal [Holy] Spirit willingly offered Himself unblemished [that is, without moral or spiritual imperfection as a sacrifice] to God, cleanse your conscience from dead works and lifeless observances to serve the ever living God?