It is narrated from Sayyidah Umm Kulthum bint Uqbah (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: "The most excellent charity is that given to a relative who harbours rancour in his heart."
Hadith Referenceالمعجم الكبير للطبراني / مسند النساء / 21666