Sayyiduna Ibn Abbas (may Allah be pleased with them both) said: I wish that people would content themselves with a quarter instead of a third (in bequests), (because) the Messenger of Allah (peace and blessings be upon him) said: "A third, and a third is a lot, or a large amount."
Hadith Referenceالمعجم الكبير للطبراني / باب العين / 10673