Who the Ahlul Bayt are
Three Quranic passages carry the Shia understanding of the household. The verse of purification speaks of God removing impurity from the household of the Prophet; the verse of affection makes love for the near of kin the response asked of the community; and the verse of mubahala names the Prophet's sons, women and own self in a solemn invocation.
The third of these is the most exacting, because it identifies people rather than a category. Who is included, and whether the phrase covers the wives as well, is precisely the kind of question this platform refuses to settle by assertion — the dossier pages record what each tradition transmits, in which source, with which authentication, and whether the record supports the conclusion drawn from it.
Read the Quranic anchors first and the dossier second. The Historical Research Center exists for that second step: it separates a reported event, a transmission, a scholarly authentication, a theological interpretation and a modern reconstruction, and it labels each one so that a reader can tell what kind of statement they are looking at.
Quran
وَقَرْنَ فِى بُيُوتِكُنَّ وَلَا تَبَرَّجْنَ تَبَرُّجَ ٱلْجَٰهِلِيَّةِ ٱلْأُولَىٰ ۖ وَأَقِمْنَ ٱلصَّلَوٰةَ وَءَاتِينَ ٱلزَّكَوٰةَ وَأَطِعْنَ ٱللَّهَ وَرَسُولَهُۥٓ ۚ إِنَّمَا يُرِيدُ ٱللَّهُ لِيُذْهِبَ عَنكُمُ ٱلرِّجْسَ أَهْلَ ٱلْبَيْتِ وَيُطَهِّرَكُمْ تَطْهِيرًۭا
And abide in your houses and do not display yourselves as [was] the display of the former times of ignorance. And establish prayer and give zakah and obey Allah and His Messenger. Allah intends only to remove from you the impurity [of sin], O people of the [Prophet's] household, and to purify you with [extensive] purification.
ذَٰلِكَ ٱلَّذِى يُبَشِّرُ ٱللَّهُ عِبَادَهُ ٱلَّذِينَ ءَامَنُوا۟ وَعَمِلُوا۟ ٱلصَّٰلِحَٰتِ ۗ قُل لَّآ أَسْـَٔلُكُمْ عَلَيْهِ أَجْرًا إِلَّا ٱلْمَوَدَّةَ فِى ٱلْقُرْبَىٰ ۗ وَمَن يَقْتَرِفْ حَسَنَةًۭ نَّزِدْ لَهُۥ فِيهَا حُسْنًا ۚ إِنَّ ٱللَّهَ غَفُورٌۭ شَكُورٌ
It is that of which Allah gives good tidings to His servants who believe and do righteous deeds. Say, [O Muhammad], "I do not ask you for this message any payment [but] only good will through kinship." And whoever commits a good deed - We will increase for him good therein. Indeed, Allah is Forgiving and Appreciative.
فَمَنْ حَآجَّكَ فِيهِ مِنۢ بَعْدِ مَا جَآءَكَ مِنَ ٱلْعِلْمِ فَقُلْ تَعَالَوْا۟ نَدْعُ أَبْنَآءَنَا وَأَبْنَآءَكُمْ وَنِسَآءَنَا وَنِسَآءَكُمْ وَأَنفُسَنَا وَأَنفُسَكُمْ ثُمَّ نَبْتَهِلْ فَنَجْعَل لَّعْنَتَ ٱللَّهِ عَلَى ٱلْكَٰذِبِينَ
Then whoever argues with you about it after [this] knowledge has come to you - say, "Come, let us call our sons and your sons, our women and your women, ourselves and yourselves, then supplicate earnestly [together] and invoke the curse of Allah upon the liars [among us]."