The noun hur - rendered by me as "companions pure" - is a plural of both ahwar (masc.) and hawra' (fem.), either of which describes "a person distinguished by hawar", which latter term primarily denotes "intense whiteness of the eyeballs and lustrous black of the iris" (Qamus). In a more general sense, hawar signifies simply "whiteness" (Asas) or, as a moral qualification, "purity" (cf. Tabari, Razi and Ibn Kathir in their explanations of the term hawariyyun in 3:52). Hence, the compound expression hur 'in signifies, approximately, "pure beings [or, more specifically, "companions pure"], most beautiful of eye" (which latter is the meaning of 'in, the plural of a'yan). In his comments on the identical expression in 52:20, Razi observes that inasmuch as a person's eye reflects his soul more clearly than any other part of the human body, 'in may be understood as "rich of soul" or "soulful". As regards the term hur in its more current, feminine, connotation, quite a number of the earliest Qur'an-commentators - among them Al-Hasan al-Basri - understood it as signifying no more and no less than "the righteous among the women of the human kind" (Tabari) - "[even] those toothless old women of yours whom God will resurrect as new beings" (Al-Hasan, as quoted by Razi in his comments on 44:54). See in this connection also note [46] on 38:52.