The phrase, "The law of the government [lit. "King"] is the law": Nedarim 28a
The power of the government to collect taxes: Nedarim 28a; Bava Metzia 73b Cheating on taxes: Pesachim 112b
Illegal taxation: Nedarim 28a
The power of a government to sell someone as a slave if he fails to pay his taxes: Bava Metzia 73b