At that time: The Pharisees came to Jesus tempting Him and saying: Is it lawful for a man to put away his wife for every cause?
Who, answering, said to them: Have ye not read, that He who made man from the beginning, made them male and female? And that He said: For this cause shall a man leave father and mother, and shall cleave to his wife, and they shall be two in one flesh. Therefore they are now not two, but one flesh. What therefore God hath joined together, let no man put asunder.
– Matthew 19:3-6