Genesis 2:18-25 (ESV)

18  Then the LORD God said, “It is not good that the man should be alone; I will make him a helper fit for him.” 

19 Now out of the ground the LORD God had formed every beast of the field and every bird of the heavens and brought them to the man to see what he would call them. And whatever the man called every living creature, that was its name. 

20 The man gave names to all livestock and to the birds of the heavens and to every beast of the field. But for Adam there was not found a helper fit for him.

21 So the LORD God caused a deep sleep to fall upon the man, and while he slept took one of his ribs and closed up its place with flesh. 

22 And the rib that the LORD God had taken from the man he made into a woman and brought her to the man.

23 Then the man said,

“This at last is bone of my bones

and flesh of my flesh;

she shall be called Woman,

because she was taken out of Man.”

24  Therefore a man shall leave his father and his mother and hold fast to his wife, and they shall become one flesh. 

25 And the man and his wife were both naked and were not ashamed.

Ephesians 5:31-32

31 “Therefore a man shall leave his father and mother and hold fast to his wife, and the two shall become one flesh.” 

32 This mystery is profound, and I am saying that it refers to Christ and the church.