أَرْبَعَةٌ لَا يَرِثُ مَعَهُمْ أَحَدٌ إِلَّا زَوْجٌ أَوْ زَوْجَةٌ الْأَبَوَانِ وَ الِابْنُ وَ الِابْنَةُ هَذَا هُوَ الْأَصْلُ لَنَا فِي الْمَوَارِيثِ فَإِذَا تَرَكَ الرَّجُلُ أَبَوَيْنِ وَ ابْنَ ابْنٍ وَ ابْنَ ابْنَةٍ فَالْمَالُ لِلْأَبَوَيْنِ لِلْأُمِّ الثُّلُثُ وَ لِلْأَبِ الثُّلُثَانِ لِأَنَّ وُلْدَ الْوَلَدِ إِنَّمَا يَقُومُونَ مَقَامَ الْوَلَدِ إِذَا لَمْ يَكُنْ هُنَاكَ وَلَدٌ وَ لَا وَارِثٌ غَيْرُهُ وَ الْوَارِثُ هُوَ الْأَبُ وَ الْأُمُ وَ قَالَ الْفَضْلُ بْنُ شَاذَانَ رَحِمَهُ اللَّهُ خِلَافَ قَوْلِنَا فِي هَذِهِ الْمَسْأَلَةِ وَ أَخْطَأَ قَالَ إِنْ تَرَكَ ابْنَ ابْنَةٍ وَ ابْنَةَ ابْنٍ وَ أَبَوَيْنِ فَلِلْأَبَوَيْنِ السُّدُسَانِ وَ مَا بَقِيَ فَلِابْنَةِ الِابْنِ مِنْ ذَلِكَ الثُّلُثَانِ وَ لِابْنِ الِابْنَةِ مِنْ ذَلِكَ الثُّلُثُ تَقُومُ ابْنَةُ الِابْنِ مَقَامَ أَبِيهَا وَ ابْنُ الِابْنَةِ مَقَامَ أُمِّهِ وَ هَذَا مِمَّا زَلَّ بِهِ قَدَمُهُ عَنِ الطَّرِيقِ الْمُسْتَقِيمَةِ وَ هَذَا سَبِيلُ مَنْ يَقِيسُ.
"There are four individuals with whom no one else shares inheritance except a husband or wife: the father, the mother, the son, and the daughter. This is the foundational principle for us in matters of inheritance. If a man dies leaving behind his parents, a grandson (son of his son), and a granddaughter (daughter of his daughter), the inheritance is divided between the parents: one-third for the mother and two-thirds for the father. This is because the descendants of children (grandchildren) only inherit in place of the child when there are no direct children or other heirs. In this case, the father and mother are the direct heirs. Al-Fadl ibn Shadhan (may Allah (swt) have mercy on him) held a differing opinion in this matter and erred. He stated that if a man leaves behind a granddaughter through his daughter, a granddaughter through his son, and both parents, then the parents receive one-sixth each, and the remainder is divided: two-thirds to the granddaughter from the son and one-third to the grandson from the daughter. He reasoned that the granddaughter through the son stands in place of her father, and the grandson through the daughter stands in place of his mother. However, this opinion deviates from the correct path and reflects the reasoning of those who rely on analogical deduction (qiyas)."