lay down the law
US /leɪ daʊn ðə lɔː/
UK /leɪ daʊn ðə lɔː/

1.
menetapkan aturan, memberi perintah
to tell people what they must do, without caring about their opinions
:
•
The new manager immediately laid down the law about punctuality.
Manajer baru segera menetapkan aturan tentang ketepatan waktu.
•
My parents always lay down the law when it comes to my curfew.
Orang tua saya selalu menetapkan aturan ketika menyangkut jam malam saya.