Mark 10:8

and the two shall be one'; so that they are two no longer, but 'one.'

1 Corinthians 6:16

Or do you not know that a man who has to do with a prostitute is one with her in body? For God says, "The two shall become one."

Ephesians 5:28

So too married men ought to love their wives as much as they love themselves. He who loves his wife loves himself.

Treasury of Scripture Knowledge

Summary

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

General references

Bible References

One flesh

1 Corinthians 6:16
Or do you not know that a man who has to do with a prostitute is one with her in body? For God says, "The two shall become one."
Ephesians 5:28
So too married men ought to love their wives as much as they love themselves. He who loves his wife loves himself.

General references

Ephesians 5:31
"For this reason a man is to leave his father and his mother and be united to his wife, and the two shall be as one."