Prophet Muhammad 
urged in the past two hadeeths to adhere to his noble household, to know their right, to respect them, and to honor them, may Allah be pleased with them all. But the question is; who are the household of Prophet Muhammad ?
Hadeeth Al-Thiqlayn indicates to the concept of the Prophet’s household clarifying that Ahl Al-Bayt are the relatives of Prophet Muhammad and his wives.
To the completion of the previous hadeeth, The companion of the prophet Zayd who narrated Hadeeth Al-Thiqalyn says: “his wives are among his household, but his household are those who charity is forbidden upon them.” One asked: “and who are they?” Zayd answered that they were the household of Ali, household of Aqeel, household of Jaffar, and household of Abbas. The first person asked again: “Upon all of them charity is forbidden?” and Zayd answered by a yes”
Abdulrahman bin Abi Layla, a dignified Companion, says: “Once we asked Prophet Muhammad about how to pray on his household although Allah told us how to pray on him. Prophet Muhammad answered: “Say: ‘O’ Allah send prayers upon Muhammad and the family of Muhammad, just as You sent prayers upon Ebraheem and the family of Ebraheem. Verily, You are full of praise and majesty. O’ Allah, send blessings upon Muhammad and the family of Muhammad, just as You sent blessings upon Ebraheem and upon the family of Ebraheem. Verily, You are full of praise and majesty.”
Then Prophet Muhammad taught them other forms of prayers upon him and his family, and one of the forms is: “O’ Allah, send prayers upon Muhammad and upon the wives and descendants of Muhammad, just as you sent prayers upon the family of Ebraheem, and send blessings upon Muhammad and upon the wives and descendants of Muhammad, just as You sent blessings upon the family of Ebraheem. Verily, You are full of praise and majesty.”
Although the wives of Prophet Muhammad are named as Ahl Al-Bayt in the Ebraheemite Prayer, we would find a better and a clearer declaration that the wives of the Prophet are his household in this narration:
Anas bin Malik reported: “A banquet of bread and meat was held on the occasion of the marriage of the Prophet to Zainab bint Jahsh. I was sent to invite the people (to the banquet), ………. The Prophet left and went towards the dwelling place of Aisha and said, "Peace and Allah's Mercy be on you, O the people of the house!" She replied, "Peace and the mercy of Allah be on you too. How did you find your wife? May Allah bless you. Then he went to the dwelling places of all his other wives and said to them the same as he said to Aisha and they said to him the same as Aisha had said to him.” (Saheeh Al-Bukhari, Tafseer Al-Quran, Surat Al-Ahzab), (Al-Nisa’ei, Work of the day and night, 271)
In the hadeeth of Al-Efk (the narration of the Lie), the Prophet , while he was on the pulpit narrating charges of adultery from Ubaydillah bin Abi Salool against the Mother of Beleivers, Aisha, says: “O people give me your opinion regarding those people who made a forged story against my family. By Allah, I do not know anything bad about her. By Allah, they accused her of being with a man about whom I have never known anything bad, and he never entered my house unless I was present there, and whenever I went on a journey, he went with me” (Saheeh Al-Bukhari, Tafseer AL-Quran, Surat AL-Nour)
Now, let us see what language has to say about this issue. Arabic Language scholars are very clear in identifying the wives of a man as his household. Ibn Manthoor says in the Tongue of the Arabs (Lisan Al-Arab): “Ahl Al-Bayt: its dwellers, Ahl Al-Rajul (family of a man) is the closest people to him, and the household of Prophet Muhammad may Allah have peace on him is his wives, his daughters, and his son-in-law who is Ali bin Abi Talib”
Al-Fayrooz Al-A’abadi says in Qamoos Al-Muheet: “Ahl Al-Amr is its rulers, Ahl Al-Bayt is its dwellers, Ahl Al-Mathhab (sect) is its who believe in it, Ahl Al-Rajul is his wife, and Ahl Al-Nabi is his wives, his daughters, and his son-in-law i.e. Ali may Allah be pleased of him.”
Al-Zubaydi says in Taj Al-Aroos (The Bride’s Crown): “Ahl Al-Mathhab is its believers, Ahl Al-Rajul is his wife and children, and this is how the verse: “and was travelling with his family” is explained as his wives and family. Ahl Al-Nabi is his wives, daughters, and his son-in-law Ali. It was said that the descendant of a man is Ahl Al-Rajul. In the Quran: “Enjoin prayer on thy family, and be constant therein,” “And Allah only wishes to remove all abomination from you, ye Members of the Family, and to make you pure and spotless,” and “let mercy of Allah and His blessings be upon you Ahl Al-Bayt, He is the most benign and most exalted.”
In addition to the Prophetic narrations and to the Arabic Language scholars’ sayings, the Quran itself testifies that wives are included in the phrase “Ahl A-Bayt.”
The Quran called Prophets’ wives as their household. Allah says: “so he said to his family, "Tarry ye; I perceive a fire; perhaps I can bring you some burning brand therefrom, or find some guidance at the fire”. And it is known that only Mousa’s wife was with him and no one else.
In the story of Zaleekha, the wife of Al-Azeez, when she wanted to temp Yousif, Allah says: “She said: "What is the (fitting) punishment for one who formed an evil design against thy family, but prison or agrievous chastisement?"
Also, Allah says: “Now when Moses had fulfilled the term, and was travelling with his family.” Al-Qumi says in his Tafseer: “When the time had come, Mousa took his wife, Shu’ayb provided Mousa, and Mousa lead his goats. When Mousa wanted to leave, Shu’ayb told him: “Go, Allah made it privately for you.” Therefore, Mousa lead his goats aiming Egypt. Mousa and his wife were in a place when a cold breeze, wind and darkness stroked Mousa and his family. Then, Mousa saw a fire, where Allah said the verse: “Now when Moses had fulfilled the term, and was travelling with his family.”
Included in the term “Ahl Al-Bayt” are Ali, Al-Hasan, Al-Hussain, and Fatima, may Allah be pleased with them all as it is mentioned in Hadeeth Al-Kisa’a (the narration of the cloak) that is narrated by Muslim. The mother of Believers, Aisha says: “One day, the messenger of Allah left the house at the afternoon and he was wearing a cloak. Then Hasan bin Ali came and the Prophet took him under his cloak. Next Hussain bin Ali came and the Prophet took him under his cloak. After that Fatima came and the Prophet took her under his cloak. Finally, Ali came, and the Prophet took him under his cloak. Then the Prophet said: “And Allah only wishes to remove all abomination from you, ye Members of the Family, and to make you pure and spotless”
In retrospect, it is cleared that the household of Prophet Muhammad are his wives, the family of Ali (Hasan, Hussain, and Fatima), the family of Aqeel, the family of Abbas, and the family of Jaffar. Those are the ones who Prophet Muhammad ordered us to dignify and respect. Hadeeth Al-Thiqlain did not testify to the infallibility of anyone of them, but raised their status. Using the verse of Purification and hadeeth Al-Kisa’a to prove Ali’s infallibility is non-sense. We prove that in another article under the title “The purification verse & Hadeeth Al-kisa'a A Scientific Dialogue.” Please refer to it.