The phrasal verb lay down in use
To lay down something means
A) to put something down to show that you're not going to use it again, typically a weapon or tool
- Lay down your weapons!
B) to give an official statement how something should be done
- The government has laid down tough anti money laundering rules for banks.
C) to lay down the law - an established idiom meaning demanding complete obedience from someone
- The kids had been misbehaving for so long that I had to lay down the law and spell out the consequences of further disobedience.