How is the marriage of a man to his son’s slave woman reconciled with the statement “and the wives of your sons”?

Question : And this is what Jaza' ibn Nawaf says, what? Al-'Anazi, okay. We chose the permissibility of a man marrying his son’s slave woman, but does it pose a difficulty for him regarding the saying of Allah the Exalted, “and the wives of your sons”? It is well known that it is permissible for the son to have intercourse with his slave woman. We ask you for guidance on how this is? We stipulated this, and this is what Jaza' ibn Nawaf says, what? Al-'Anazi, okay. We chose the permissibility of a man marrying his son’s slave woman, but does it pose a difficulty for him regarding the saying of Allah the Exalted, “and the wives of your sons”? It is well known that it is permissible for the son to have intercourse with his slave woman. We ask you for guidance on how this is? We stipulated this, and this is what Jaza' ibn Nawaf says, what? Al-'Anazi, okay. We chose the permissibility of a man marrying his son’s slave woman, but does it pose a difficulty for him regarding the saying of Allah the Exalted, “and the wives of your sons”? It is well known that it is permissible for the son to have intercourse with his slave woman. We ask you for guidance on how this is? We stipulated this, yes?

Answer : We stipulated two conditions: that it is permissible for him to marry a believing woman, and second, that the son has not had intercourse with her, clear?