It is narrated from Sayyiduna Ali (may Allah be pleased with him) that two sons of a paternal uncle were brought to him, one of whom was a maternal half-brother. Sayyiduna Ali (may Allah be pleased with him) was told: Abdullah (may Allah be pleased with him) used to give the whole property to the maternal half-brother. Sayyiduna Ali (may Allah be pleased with him) said: "May Allah have mercy on him; although he was a jurist, had it been me, I would have given the maternal half-brother a sixth, then divided the rest between the two of them."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الفرائض / 12378