Sunan Ibn Majah, Volume 4, Book 23, Hadith 2723 (DarusSalam) ⓘ
It was narrated that Ma’qil bin Yasar said: “The Messenger of Allah ruled concerning a grandfather who was among us, that he should receive one sixth.”
قَالَ أَبُو الْحَسَنِ الْقَطَّانُ حَدَّثَنَا أَبُو حَاتِمٍ، حَدَّثَنَا ابْنُ الطَّبَّاعِ، حَدَّثَنَا هُشَيْمٌ، عَنْ يُونُسَ، عَنِ الْحَسَنِ، عَنْ مَعْقِلِ بْنِ يَسَارٍ، قَالَ قَضَى رَسُولُ اللَّهِ صلى الله عليه وسلم فِي جَدٍّ كَانَ فِينَا بِالسُّدُسِ .
also referenced under: Hadith 2723 (Reference) & Book 23, Hadith 2827 (In-Book)