Musnad Abu Ya'la al-Mawsili 246:1

Zuhayr ibn Harb narrated to us, Sufyan ibn 'Uyaynah narrated to us, from al-Zuhri, from Muhammad ibn Jubayr ibn Mut'im, from his father, from the Prophet (peace and blessings of Allah be upon him), who said: "The severer [of kinship ties] shall not enter Paradise."