Quran about the Kin

Surah 8 (Al‑Anfaal), Ayah 75 signifies the blood relations.

…وَأُوْلُواْ الأَرْحَامِ بَعْضُهُمْ أَوْلَى بِبَعْضٍ فِي كِتَابِ اللّهِ

إِنَّ اللّهَ بِكُلِّ شَيْءٍ عَلِيمٌ

... and the blood relations are nearer to one another in the Book of Allah.  Certainly Allah knows all.

Commentary

In Al‑Nusoos, Al‑Siddooq quotes Imam Al-Husain who said when Allah sent down this Ayah —the blood relations are nearer one to another in the Book of Allah— Husain asked his grandfather (the Prophet) for explanation.  The Prophet (pbuh) answered, “Grandson, when I die, your father, Ali, who is nearest to me, has the Supreme Title over anybody else for succeeding me.  When your father passes away then your brother Al‑Hasan has the Supreme Title over others, and when Al‑Hasan passes away, you have the Supreme Title for succeeding him.”