Jami` at-Tirmidhi Book 27, Hadith 15
the Messenger of Allah said: "The one who severs ties will not enter Paradise." Ibn Abi 'Umar said: "Sufyan said: 'Meaning: Ties of the womb."
the Prophet said: "Merely maintaining the ties of kinship is not adequate. But connecting the ties of kinship is when his ties to the womb are severed and he connects it."
'a righteous woman, Khawlah bint Hakim said: "The Messenger of Allah came out during the middle of the day, while holding one of the sons of his daughter in his arms. He was saying: 'You are what makes them stingy, cowardly and ignorant. And you are but Raihanillah