And as for the union of kinship, they (kinship) are blood ties. 


For Allāh Ta`ālā said in the order of connecting bonds with them: "Give the kinsman his due" [17:26]. And in an elucidation of honour for the nation He chose and was delighted with, He Ta`ālā said: "And those who join that which Allāh has commanded to be joined and fear their Lord, and dread the terrible reckoning " [13:21], from what Allāh ordered as per "to be joined ": kinship bonds.

Union of Kinship
Imām al-Habīb `Abdullāh al-Haddād