Ancestral Laws

Ancestral Laws is a set of scrolls, written by the very first king of the new dynasty. While a famous and capable general, well versed in strategy and military affairs by his own experiences through conquering the land back from the hands of the barbarians, he was not an intelligent person. Clever, cunning and smart, yes, but not well educated and he was fully aware of his shortcomings, due to the fact that he was not born into nobility but into a simple peasant family. He knew the people and the people knew him which was why his rebellion led to a succesful uprising against the usurpors and eventually turned into establishing an entire new order in the land.
This set of scrolls is a message from the king to his people, stating that their interests should always be the top concern of the ruling class. While the right to govern is still given out by gods and the heaven above and rising to the nobility or among the ministers must only be through the play of fate or life - meaning it should be the merit of your soul and not a result of bribery or any other not-so-godly means.
He then comissioned a group of famous scholars to look through history and all lines of society to put together principles that should guide the entire society and the ruling class as well. These individual principles were also issued as letters of the king to his people and after his death are displayed in his tomb which because a holy place of prayer and reverence.
One of the unique features of these laws is the principle that the higher your status in society, the more severe your punishment for any transgressions will be. That's why kids are able to get away with lying or even stealing more or less unharmerd, meanwhile if you as a noble lie to your king, you might very well lose your head if the lie is severe enough.