Sayyiduna Abu Bakrah (may Allah be pleased with him) said that the Messenger of Allah (peace and blessings be upon him) said: "Transgression and severing the ties of kinship are sins for which Allah gives punishment in this world as well as storing up (punishment) for the Hereafter."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الشهادات / 21082