Hasan al-Basri (may Allah have mercy on him) said: "In the time of ignorance, a man would make an agreement with another that 'I will be your heir and you will be mine,' so the one who made the agreement would receive one-sixth, then the rest of the heirs would divide the remaining wealth among themselves. Then Allah the Exalted abrogated this through 'But those of blood relationship are nearer to one another' [الأحزاب: 6] ."