Sayyidah Zaynab (may Allah be pleased with her), the wife of Abdullah, said: Bilal (may Allah be pleased with him) came out, and we said to him: Ask the Messenger of Allah (peace and blessings be upon him): will spending on our husbands and on those raised in our care suffice for us as charity? So he went in and asked him, and the Prophet (peace and blessings be upon him) said: "There is a double reward: the reward of charity and the reward of upholding the ties of kinship."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21096