'Is It Lawful' in the Bible

and lo, there was a man having the hand withered, and they questioned him, saying, 'Is it lawful to heal on the sabbaths?' that they might accuse him.

And the Pharisees came near to him, tempting him, and saying to him, 'Is it lawful for a man to put away his wife for every cause?'

tell us, therefore, what dost thou think? is it lawful to give tribute to Caesar or not?'