Who said "A man of the night watch knows his duty."?

This quote is attributed to Lannister.

A man of the night watch knows his duty. - Lannister

"A man of the night watch knows his duty."

Lannister Leadership

"A Lannister always pays his debts."

"I am the god of tits and wine."

"You are an awful man."

"I drink and I know things."

"A leader must be fair and just."

"Integrity is everything."

"One must take responsibility for one's environment."

"In this house, I make the decisions"