Abdul-Rahman reported,
I heard the Messenger of Allah ﷺ say, "Allah 
said, 'I am Allah, and I am ar-Rahman. I created the womb and derived its name from My own name. Whoever maintains its ties, I will maintain ties with him, and whoever severs it, I will sever him.'"
Tirmidhi 1907
Sahihحدثنا ابن أبي عمر وسعيد بن عبد الرحمن المخزومي قالا حدثنا سفيان بن عيينة عن الزهري عن أبي سلمة قال اشتكى أبو الرداد الليثي فعاده عبد الرحمن بن عوف فقال خيرهم وأوصلهم ما علمت أبا محمد
فقال عبد الرحمن
سمعت رسول الله ﷺ يقول قال الله تبارك وتعالى أنا الله وأنا الرحمن خلقت الرحم وشققت لها من اسمي فمن وصلها وصلته ومن قطعها بتته
[Sahih]. Abu Dawud also narrated it in the Book of Zakat, Chapter on Maintaining Family Ties, no. 1694, from the hadith of Sufyan bin Uyayna, with the same chain. The hadith has corroborating narrations in Ahmad 1/11, 194, 22/498 and elsewhere. See also Musnad Humaydi (my edition), no. 65.On this subject there are also narrations from Abu Saeed [Ahmad 3/14, 83], Ibn Abu Awfa [Bukhari in Adab al-Mufrad, no. 63, and Baghawi in Sharh al-Sunnah 13/28, no. 3439, 3340], Amir bin Rabia [Abu Yaala 13/156, no. 7198, and Bazzar 22/375, no. 1882], Abu Hurairah [Ahmad 2/498 and Hakim 4/157], and Jubayr bin Mutim [coming up at no. 1909].The hadith of Mamar is found in Abu Dawud, no. 1695, and Ibn Hibban graded it sahih, no. 2033. It is also found in Kitab Jami of Mamar (Abdul-Razzaq, no. 20234).