Mark 10:8

and so they are no longer two but one.

1 Corinthians 6:16

Or do you not know that a man who has to do with a prostitute makes one body with her? For "The two," says the Scripture, "shall become physically one."

Ephesians 5:28

That is the way husbands ought to love their wives??s if they were their own bodies; a man who loves his wife is really loving 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 makes one body with her? For "The two," says the Scripture, "shall become physically one."
Ephesians 5:28
That is the way husbands ought to love their wives??s if they were their own bodies; a man who loves his wife is really loving himself,

General references

Ephesians 5:31
Therefore a man must leave his father and mother and attach himself to his wife, and they must become one.