The Torah introduces us to the parameters of how one must approach marrying a captive of war (21:11-14).
What is the most famous case in Tanach of a King marrying a woman taken captive in battle (see Radak Shmuel 3:3)?
Who was their child? What does the Radak say about these types of marriages?
What values could be possibly missing from a marriage of this sort that may result in the concerns as expressed by the Radak?