Musnad Ahmad 1153:327

Waki’ narrated to us, he said: Mu’awiyah ibn Abi Muzarrad narrated to us, from Yazid ibn Ruman, from ‘Urwah ibn al-Zubayr, from ‘Aishah, she said: The Messenger of Allah, peace and blessings of Allah be upon him, said: "The kinship (al-rahim), whoever maintains it, Allah maintains him, and whoever severs it, Allah severs him."