That a wife must not depart from her husband; or if she should depart, she must remain unmarried
In the first Epistle of Paul to the Corinthians: “But to them that are married I command, yet not I, but the Lord, that the wife should not be separated from her husband; but if she should depart, that she remain unmarried or be reconciled to her husband: and that the husband should not put away his wife.”
Source: The Treatises of Cyprian (New Advent)