Before God and eyewitnesses, the bride and groom exchange their marriage vows. They usually promise that they will love, cherish, and respect each other and that they will do so “for aslong as [they] both shall live together on earth according to God’s marital arrangement.”
With this sentence in §14 they cleverly prepare the reader when the separation from a partner who leaves the "truth" is allowed.
"usually" - I never heard marriage vows like this.