This can be proved from the saying of Almighty...
He said: O Nuh! surely he is not of your family. (Qur’an, Surah Hud 11:45-46) There is a tradition of the Holy Prophet (S) that he said: Salman is from us, Ahle Bayt. And the saying of the Imams (as): Our Shias are from us and they shall return to us. In Tafseer Burhan etc it is narrated from Umar bin Yazid Thaqafi that he said: His Eminence, Imam Sadiq (as) told me: O son of Yazid, you are, by Allah, from us. And I asked him: May I be sacrificed on you, from Aale Muhammad?
فَمَنْ تَبِعَنِي فَإِنَّهُ مِنِّي ۖ وَمَنْ عَصَانِي فَإِنَّكَ غَفُورٌ رَحِيمٌ Then whoever follows me, he is surely of me, and whoever disobeys me, You surely are Forgiving, Merciful. (Qur’an, Surah Ibrahim 14:36) There are numerous traditions in this meaning but what we have related so far would be sufficient for the people of insight. [^1]: Khisaal, Vol. 2, Pg. 579 [^2]: Tahdhib, Vol. 2, Pg. 109, Tr. no. 179 [^3]: Tafseer Al-Burhan, Vol. 1/290 & Previous…