Sayyiduna Zayd (may Allah be pleased with him) said: "O Commander of the Believers! Do not take the likeness of a tree that grows, from which a branch comes out, and from that branch two branches come out; how then do you make the first more entitled than the second, when both came out of the first?" Then Umar (may Allah be pleased with him) asked Sayyiduna Ali (may Allah be pleased with him), saying to him what he had said to Zayd (may Allah be pleased with him). Sayyiduna Ali (may Allah be pleased with him) said the same as Zayd (may Allah be pleased with him), except that Ali (may Allah be pleased with him) gave the likeness of a torrent that flows, from which a stream branches off, then two streams branch off from it, and he said: "What do you think: if the water of the middle stream dried up, would it return to both streams together?"
The Shaykh said: Abdullah bin Mas'ud (may Allah be pleased with him) used to make the grandfather share with the full and paternal brothers and sisters.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12431