As for the argument that the “Ahlul-Bayt” (members of the household) of a man is known in the Arab community to be in reference to his wives, that is a big mistake. In the Arab community, the Ahlul-Bayt of a man refers to everyone living with him including his wives, sons, daughters, grandparents, and grandchildren.
The poems of the days of ignorance, the news reports, and the ancient Arab stories all indicate that. No one ever claimed that the “Ahlul-Bayt” of a man is only his wives. They are included in this expression, but it is not restricted to them. It is true that Allah (SWT) used the term “Ahlul-Bayt” when addressing Sarah, the wife of Abraham (AS). But He also used the term “Ahl” when referring to the sons of a man.
For instance, in response to Prophet Nuh (AS) when he cried out to Him,
“Surely my son is of my family (Ahl).” [11:35]
Allah (SWT) said,
“Oh Nuh! Surely, he is not of your family, surely he is (the doer of) other than good deeds.” [11:36]
This indicates that the “Ahl” of a man may include his sons. Allah (SWT) also used this term in reference to the daughters of a man. For example, He said to Prophet Lut (AS),
“So remove your family (Ahl) in a part of the night.” [11:81]
And those whom Prophet Lut went with were his daughters while his wife perished with those who perished. Hence, the use of the terms “Ahl” and “Ahlul-Bayt” are not restricted to the wives.
In addition, Allah’s speech to Sarah, the wife of Abraham (AS) does not necessarily mean that she alone is meant by “Ahlul-Bayt”. He says to her,
“The mercy of Allah and His blessing are on you, O People of the House.” [11:73]
This verse refers to her, her husband, her expected newborn, all the sons of her husband, Hajar, Ismael (AS), and her grandchild, Ya’qoob (AS). All those individuals are considered to be the People of the House (Ahlul-Bayt) of Abraham (AS). So, why then, the intentional mistake of claiming that the Ahlul-Bayt of a man refers only to his wives? Why the wrong deduction and speculation on what the Angels has said to Sarah, the wife of Abraham (AS)?