'Law of the Lord' in the Bible

“Even the stork in the skyKnows her seasons [of migration],And the turtledove, the swallow and the craneObserve the time of their return.But My people do not knowThe law of the Lord.

How do ye say, We are wise, and the law of the LORD is with us? Lo, certainly in vain made he it; the pen of the scribes is in vain.