'Is It Lawful' in the Bible

And he says to them, Is it lawful on the sabbath to do good or to do evil, to save life or to kill? But they were silent.

And Pharisees coming to him asked him, Is it lawful for a man to put away his wife? (tempting him).

And they come and say to him, Teacher, we know that thou art true, and carest not for any one; for thou regardest not men's person, but teachest the way of God with truth: Is it lawful to give tribute to Caesar or not?