Sa’d b. Abu Waqqas said

God’s Messenger visited me when I was ill and asked whether I had made my will. I replied that I had. He asked how much I had willed and when I told him I had willed all my property away to be devoted to God’s path he asked how much I had left my children. I replied that they were rich and prosperous, whereupon he told me to will away a tenth ; but I kept on telling him it was too little till he finally said, “Will away a third, but a third is a lot.” Tirmidhi transmitted it.