Ephesians 5:31
For this cause shall a man leave his father and mother, and shall be joined unto his wife, and they two shall be one flesh.
Cross-reference
Ephesians 5:28 applies the 'one flesh' union to husbandly love — loving wife as own body flows from becoming one flesh.
Ephesians 5:29 extends the one-flesh principle: just as we care for our own body, so husbands nourish wives as their own flesh.
Genesis 2:24 is the original creation ordinance quoted here — the one flesh union between man and wife.
Matthew 19:5 also quotes Genesis 2:24, using the same verse about leaving parents and becoming one flesh.
Mark 10:7 similarly quotes Genesis 2:24 — reinforcing the marriage foundation that Paul applies to Christ and the church.
Mark 10:8 records Jesus quoting the same Genesis verse about two becoming one flesh, affirming its authority in marriage.
1 Corinthians 6:16 cites the same 'one flesh' verse to warn against sexual immorality — a contrasting misuse of the marital union.