It is narrated from Sayyiduna Anas bin Malik (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: "Whoever would like to have his provision blessed and his life extended, let him join his ties of kinship."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب قسم الصدقات / 13221