Jami' at-Tirmidhi #2004
Sahih (Authentic)
Ties of Kinship
لَيْسَ الْوَاصِلُ بِالْمُكَافِئِ وَلَكِنِ الْوَاصِلُ الَّذِي إِذَا قُطِعَتْ رَحِمُهُ وَصَلَهَا
The Messenger of Allah (ﷺ) said: 'The one who maintains ties of kinship is not the one who reciprocates. Rather, the one who maintains ties of kinship is the one who, when his relatives cut him off, maintains his ties.'
Chain of Narration (Isnad)
Narrated Abu Huraira