According to the consensus of classical Islamic scholarship, Quran 4:24 establishes a fundamental principle of Islamic family law: the prohibition of marrying women who are already in a valid marriage ('al-muhsanat'). Tafsir Ibn Kathir clarifies that this divine decree is binding, thereby safeguarding the sanctity of existing unions and preventing polyandry. The verse then opens the door to lawful marriage with all other women not mentioned in the prohibited categories (see 4:23), on the condition that the marriage is sought with a dower from one's wealth ('bi-amwalikum') and with the sincere intention of 'desiring chastity, not unlawful sexual intercourse' ('muhsinina ghayra musafihin'). This synthesis, supported by commentators like Al-Jalalayn and Maududi, illustrates that the verse, by forbidding marriage to the married, inherently guides believers towards marrying those who are single—be they unmarried, widowed, or divorced—through a sanctified and responsible contract.