Asma bint Abi Bakr (may Allah be pleased with her) said: I asked the Messenger of Allah (peace and blessings be upon him): My mother comes to me and she is desirous (of my kindness); shall I give to her? He (peace and blessings be upon him) said: "Yes, maintain ties of kinship with her."
Hadith Referenceالسنن الكبرى للبيهقي / كتاب الزكاة / 7843