Musnad Ahmad 658:139

Mu'ammar ibn Sulayman al-Raqqi narrated to us, al-Hajjaj narrated to us, from Abu Ishaq, from al-Bara' ibn 'Azib, who said: The Messenger of Allah (peace and blessings of Allah be upon him) was asked about the *kalalah* (a person who dies leaving neither ascendants nor descendants as heirs), and he said: "The summer verse is sufficient for you."