Gospel according to Saint Mark 10,1-12
Jesus went to the province of Judea, beyond the Jordan River. Once more crowds gathered around him and once more He taught them, as He always did. Some (Pharisees came and) put him to the test with this question, «Is it right for a husband to divorce his wife?». He replied, «What law did Moses give you?». They answered, «Moses allowed us to write a certificate of dismissal in order to divorce». Then Jesus said to them, «Moses wrote this law for you, because you are stubborn. But in the beginning of creation God made them male and female, and because of this, man has to leave father and mother and be joined to his wife, and the two shall become one body. So they are no longer two but one body. Therefore let no one separate what God has joined».
When they were indoors at home, the disciples again asked him about this and He told them, «Whoever divorces his wife and marries another commits adultery against his wife, and the woman who divorces her husband and marries another also commits adultery».