وَعَنْ بُرَيْدَةَ
أَنَّ النَّبِيَّ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ جَعَلَ لِلْجَدَّةِ السُّدُسَ إِذَا لَمْ تَكُنْ دونهَا أم
The Prophet (sallallahu alayhi wa sallam) appointed a sixth to a grandmother if no mother is left to inherit before her.
Mishkat al-Masabih 2926, Book 13, Inheritance and Wills, Hadith 8. 1 min read