Musannaf Ibn Abi Shayba 26:209

Abu Mu'awiyah narrated to us, from al-A'mash, from Ibrahim, who said: 'Abdullah used to make the *al-Akdariyyah* (inheritance case) out of eight: three for the husband, three for the sister, one share for the mother, and one share for the grandfather. He said: And 'Ali used to make it out of nine: three for the husband, three for the sister, two shares for the mother, and one share for the grandfather. And Zayd used to make it out of nine: three for the husband, three for the sister, two shares for the mother, and one share for the grandfather. Then he would multiply it by three, so it becomes twenty-seven; he would give the husband nine, the mother six, and twelve would remain, so he would give the grandfather eight and give the sister four.