Sahih Bukhari
Good Manners and Form (Al-Adab)
Volume: 008 / Book Number: 073 / Hadith Number: 20
Narrated Abdullah bin 'Amr:
The Prophet said, "Al-Wasil is not the one who recompenses the good done to him by his relatives, but Al-Wasil is the one who keeps good relations with those relatives who had severed the bond of kinship with him."