1 Corinthians 7:10-12

10But to the married I enjoin, not I, but the Lord, Let not wife be separated from husband;

11(but if also she shall have been separated, let her remain unmarried, or be reconciled to her husband;) and let not husband leave wife.

12But as to the rest, I say, not the Lord, If any brother have an unbelieving wife, and she consent to dwell with him, let him not leave her.