Answer
In the name of Allah, be advised that the privilege of Ahlulbait (PBUH) to the wives of the prophet (PBUH&HF) should not be hidden from the one who understands Arabic. There is no way to interpret – as the exponents do- that the rulings related to Ahlulbait (PBUH) include the wives of the prophet (PBUH&HF). Though the verses were revealed in favor of Ahlulkissa (the infallibles who were under the groan of the prophet (PBUH&HF): Imams Ali, Hassan, Hussein and Lady Fatima, in addition to the prophet himself (. The fact is that the pronouns used to refer to the prophet’s (PBUH&HF) wives are used as feminine pronouns. However, the pronouns used to address which are related to the prophet’s family include feminine and masculine. Thus, it is unreasonable that the addressees include the prophet’s wives. Furthermore, the nature of the Arabic language is that it has a special system for the masculine and feminine pronouns which are different from each other. If the ruling includes both males and females, it comes in masculine forms of pronouns, and so do the males. If it is related to females, the feminine forms are used. If it is related to males and females but the males are more than the females, then as a matter of multiplicity, masculine forms are used. Ahlulkissa are four males and one female who is Lady Fatima (PBUH). As for the rulings that are related to the wives of the prophet (PBUH&HF) are all in feminine forms. This is the borderline between the ones who are concerned with the verse of Al-Tatheer and the wives of the prophet (PBUH&HF). The holy Quran is eloquent in conveying such meaning, and there is no excuse for those who have a heart or listen attentively while witnessing, regardless to the large number of the narrations concerned with the revelation of the verse of Al-Tatheer.
You should know that including all the verses related to Ahlulkissa (PBUH) within the rules of the prophet’s wives only show the greatness of Ahlulbait (PBUH), just like when you put white near black, the black makes the white brighter, and the white makes the black darker. Allah says: “believers are representatives of one another” showing the characteristics of the believers, and right after this verse the verse “the hypocrites represent one another” showing the contradicting characteristics of the hypocrites, as in the chapter of the Zumar “the ones who are unbelievers have been sent off to the hell in cohorts”. It is known that sending people to the hell is done involuntarily and by coercion - may Allah forbid. After this verse, “the ones who are believers have been sent to the heaven in groups.” It is known that sending the believers is recognized with respect and dignity from Allah to those who love Allah, and thus Allah has graced them with entering the heaven. Therefore, sending the criminals is humiliation and insult while sending the righteous ones is honoring and reverence so that the righteous is differentiated form the sinners. The righteous ones and sinners are recognized. In such similar way, Allah wants to distinguish Ahlulkissa (PBUH) from all the other ones who are related to the prophet (PBUH) through marriage. Allah is the all Guide and Knowing.