Germany passed the Nuremberg law in order to protect the German blood by avoiding the marriage between Jews and German.
Explanation:
The ultimate goal of such laws passed by Nazi Germany was to ultimately remove the Jews from the power and administrative positions in Germany.
The Nuremberg law was passed with the aim to protect the German blood which could be done by stopping the German Jew marriage and any extramarital intercourse between those races.
Although this was a racist law, it was passed with a motive to form a strong central government based upon the racism- eliminating Jews from power and suppression of those races by stripping off their citizenship and civil rights.