Tafsir of Hud 11:79

"They said," turning away from what he had advised them with—namely, the command to fear Allah and the prohibition of disgracing him—concerning the beginning of his speech, "You know that we have no right to your daughters." The term "right" refers to a claim; they meant by this the satisfaction of desire—that is, "We have no need for your daughters." It is also interpreted as that which contradicts falsehood, meaning, "We have no rightful marriage to your daughters, for you do not see our marriage to Muslim women as permissible." This is merely a superficial claim, and it is evident from this that it was part of his—peace be upon him—law that the marriage of a disbeliever to a Muslim woman was not lawful.

It is also said that they only denied having a right to his daughters because they had proposed to them, and he had rejected them; and it was their custom that whoever was rejected in a marriage proposal could never be permitted to marry that woman. It is also said that when they adopted the practice of approaching males as their chosen path, they considered it the "right," while the marriage of females was "falsehood," and so they said what they said. It is also said that they said this because their custom was that a man among them would not marry more than one woman, and they were all already married.

"And you surely know what we want," meaning the approaching of males. It is apparent that "what" (mā) is the object of "you know," and it is in the sense of "recognize," functioning as a relative pronoun with the referent omitted—that is, "what we want." It is also said that it is a verbal particle (masdariyyah), so there is no omission, meaning "our desire." It is further permitted that it be an interrogative, serving as the object of "we want," in which case it suspends the verb "to know." When he—peace be upon him—despaired of them desisting from the path of error upon which they were, [the narrative continues].