7. You do not commit adultery.
Let's begin with the definition of adultery. Committing adultery means having sexual relations with someone other than a) for a man - his wife or b) for a woman -her husband. Marriage is a lifelong commitment that requires the husband and wife to be faithful to each other.
Now there are two (and only two) exceptions to marriage being a lifelong obligation. The first is divorce. Divorce is only permitted by the Torah in the case of sexual promiscuity (adultery). And second is the death which releases the woman / man from their marriage contract.
Yahushua confirms this interpretation. When asked by the Pharisees under what conditions a man may divorce his wife, he replied:
'But I tell you that anyone who divorces his wife, except for marital unfaithfulness, causes her to become an adulteress, and anyone who marries the divorced woman commits adultery.'
Fidelity and faithfulness in marriage is a testimony and picture to the faithfulness of Yahuwah and his people in a righteous Covenant relationship. This is why Yahuwah puts such value on fidelity in the marriage contract between a man and a woman.