Musnad Ahmad 10:31

Sufyan narrated to us, from al-Zuhri, from Abu Salamah, who said: Abu al-Raddad fell ill, and Abd al-Rahman ibn Awf visited him. Abu al-Raddad said: "You are the best of them and the most upholding of kinship ties, as far as I know, O Abu Muhammad." Abd al-Rahman ibn Awf said: "I heard the Messenger of Allah, peace and blessings of Allah be upon him, say: 'Allah the Almighty and Majestic said: I am Allah, and I am the Most Merciful (al-Rahman). I created the womb (al-rahim) and derived for it a name from My name. So whoever upholds it, I uphold him, and whoever severs it, I sever him.'"