Musnad Ahmad 658:205

Mu'ammar narrated to us, 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* (the person who leaves behind neither ascendants nor descendants as heirs). He said: "The summer verse is sufficient for you."