Narrated Ibn 'Abbas: I recommend that people reduce the proportion of what they bequeath by will to the fourth (of the whole legacy), for Allah's Apostle said, "One-third, yet even one third is too much."
— Sahih Bukhari, Volume 4, Book 51: Wills and Testaments (Wasaayaa), Hadith #6
Narrated Ibn 'Abbas: I recommend that people reduce the proportion of what they bequeath by will to the fourth (of the whole legacy), for Allah's Apostle said, "One-third, yet even one third is too much."
This hadith is from the book of Wills and Testaments (Wasaayaa) in Sahih Bukhari, compiled by Imam al-Bukhari. It is hadith number 6 in book 51 of volume 4.
This hadith is referenced in the following topics: Wills.