4. Humayd ibn Ziyad has narrated from al-Hassan ibn Muhammad ibn Sama‘ah who has said that abu Shu’ayb has narrated from Rifa‘ah, from Aban ibn Taghlib who has narrated the following: “I once asked abu ‘Abd Allah , about the case of a son of a brother and a grandfather. He (the Imam) said, ‘The legacy between them is half and half.’”