'According to the Law' in the Bible

And the drinking was according to the law; none did compel: for so the king had appointed to all the officers of his house, that they should do according to every man's pleasure.

Go, gather together all the Jews that are present in Shushan, and fast ye for me, and neither eat nor drink three days, night or day: I also and my maidens will fast likewise; and so will I go in unto the king, which is not according to the law: and if I perish, I perish.