Mukhtasar Bukhari

It is narrated from Sayyiduna Abdullah bin Amr (may Allah be pleased with them both) that the Noble Prophet (peace and blessings of Allah be upon him) said: "The one who maintains ties of kinship is not the one who merely reciprocates (i.e., does good only in return for good), but the one who truly maintains ties of kinship is the one who joins relations when they have been severed."