Musnad Abu Ya'la al-Mawsili 150:95

Muhammad ibn 'Abbad narrated to us, Hatim narrated to us, from Mu'awiyah ibn Abi Muzarrad, from Yazid ibn Ruman, from 'Urwah ibn al-Zubayr, from 'Aishah, who said: The Messenger of Allah (may Allah bless him and grant him peace) said: "Indeed, the kinship (al-rahim) is a branch (shujnah) from the Most Merciful (al-Rahman). Whoever maintains it, He maintains him, and whoever severs it, He severs him."