What is the ruling on one who issues a fatwa obligating the implementation of a mandatory will concerning the inheritance of the grandchildren of a deceased daughter, who died before her father, while their maternal uncle and aunt are alive?

The law of the obligatory bequest (al-wasiyya al-wājibah), which is applied in some countries, is not valid Islamically (sharʿan) and contradicts the texts of Islamic Law (Sharia). It cannot be attributed to any of the four madhhabs (schools of thought) or to the early scholars. Whoever issues a fatwa (religious edict) permitting it, while knowing its contradiction to the Sharia, has committed a grave error, because he has transgressed the bounds of Allah in the division of inheritances. Allah Almighty says: "These are the limits [set by] Allah, and whoever obeys Allah and His Messenger will be admitted by Him to gardens [in Paradise] under which rivers flow, abiding eternally therein; and that is the great attainment. But whoever disobeys Allah and His Messenger and transgresses His limits – He will admit him to a Fire, abiding eternally therein, and he will have a humiliating punishment." (Quran 4:13-14). As for one among the people of ijtihad (independent juristic reasoning) who issues a fatwa permitting it, believing in its permissibility, he will have one reward for his mistaken ijtihad. Nevertheless, it is not permissible for one who knows the truth in the matter to imitate him.