Mishkat al-Masabih 2936

'Imran b. Husain said: A man came to God’s Messenger and said, “My son’s son has died, so what do I receive from his estate?” He replied, “You receive a sixth;” then when he turned away he called him and said, “You receive another sixth;” and when he turned away he called him and said, “The other sixth is an allowance ,” (It would seem, although it is not explicit, that the grandson had left two daughters who were therefore entitled to two-thirds of the estate. The grandfather was entitled only to a sixth, but was given another sixth, as a favour, presumably because there were no other heirs). Ahmad, Tirmidhi and Abu Dawud transmitted it, Tirmidhi saying this is a hasan sahih tradition.