Hakam bin Mas'ud al-Thaqafi (may Allah have mercy on him) said: I was with Sayyiduna Umar bin al-Khattab (may Allah be pleased with him). He made the full brothers share the one-third together with the maternal half-brothers. A man said: The year before, you judged the opposite of this. He asked: What did I judge? He said: You gave a share to the full brothers and gave nothing at all to the maternal half-brothers. Sayyiduna Umar bin al-Khattab (may Allah be pleased with him) said: That stands as we judged it then, and this stands in its own place.
Hadith Referenceالسنن الكبرى للبيهقي / كتاب آداب القاضي / 20374