Muwatta Imam Malik (Riwayat Yahya)

Imam Malik, may Allah have mercy on him, said that the grandfather will inherit along with the brothers, because he has more right than them, since the grandfather also inherits a sixth share with the son, unlike the brothers and sisters. And because the grandfather is not equal to the brother; even in the presence of the deceased’s son, he takes one-sixth, so why should he not receive a third with the brothers and sisters? This is because uterine brothers and sisters take a third with full brothers and sisters. If the grandfather is also present, he will deprive the uterine brothers and sisters, then he will take the third for himself, because he is the one who deprived them. If he were not present, the uterine brothers and sisters would have taken that third. So the grandfather took the share that could not be received by the full or paternal brothers and sisters, rather it was the right of the uterine brothers and sisters, and the grandfather had more right than them, so he took it and deprived the uterine brothers and sisters.