It was narrated that Ibn Abbas said:
“I would like the people to reduce (the will) from one third to one quarter, because the Messenger of Allah ﷺ said: 'One third is a lot.'”

حَدَّثَنَا عَلِيُّ بْنُ مُحَمَّدٍ، حَدَّثَنَا وَكِيعٌ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنِ ابْنِ عَبَّاسٍ، قَالَ وَدِدْتُ أَنَّ النَّاسَ، غَضُّوا مِنَ الثُّلُثِ إِلَى الرُّبُعِ لأَنَّ رَسُولَ اللَّهِ ﷺ قَالَ " الثُّلُثُ كَبِيرٌ - أَوْ كَثِيرٌ - " .