Sahih Bukhari Volume 007, Book 070, Hadith Number 563.
Narrated By Sad : I became seriously ill at Mecca and the Prophet came to visit me. I said, "O Allah's Apostle! I shall leave behind me a good fortune, but my heir is my only daughter; shall I bequeath two third of my property to be spent in charity and leave one third (for my heir)?" He said, "No." I said, "Shall I bequeath half and leave half?" He said, "No." I said, "Shall I bequeath one third and leave two thirds?" He said, "One third is alright, though even one third is too much." Then he placed his hand on his forehead and passed it over my face and abdomen and said, "O Allah! Cure Sad and complete his emigration." I feel as if I have been feeling the coldness of his hand on my liver ever since.