1 Corinthians 7:10-12

7:10 To the married I give this command – not I, but the Lord – a wife should not divorce a husband 7:11 (but if she does, let her remain unmarried, or be reconciled to her husband), and a husband should not divorce his wife.

7:12 To the rest I say – I, not the Lord – if a brother has a wife who is not a believer and she is happy to live with him, he should not divorce her.