´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.'”
Hadith ReferenceSunan Ibn Majah / The Chapters on Wills / Hadith: 2711
Hadith Gradingالألبانی:صحيح | زبیر علی زئی:متفق عليه