Sayyiduna Abd al-Rahman bin Awf (may Allah be pleased with him) said that he heard the Prophet (peace and blessings be upon him) saying that Allah Almighty says: "I am al-Rahman (the Most Merciful), and I created al-rahim (the ties of kinship), and I took it from among My names. Whoever joins it, I will join him, and whoever cuts it off, I will cut him off."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الصدقات / 13215