Mark 10:5-9

5 And Jesus answered and said unto them, For the hardness of your heart he wrote you this precept.

6 But from the beginning of the creation God made them male and female.

7 For this cause* shall a man leave his father and mother, and cleave to his wife;

8 And they twain shall be one* flesh: so then they are no more twain, but one flesh.

9 What therefore God hath joined together, let not man put asunder.