He, sallallaahu 'alayhi wa sallam, called for the kind treatment of his relatives:

Zayd ibn Arqam (a Companion) narrated that the Prophet of Allah, sallallaahu 'alayhi wa sallam, stood up one day amongst us to give a speech at a river called Khumm between Makkah and Madinah. He, sallallaahu 'alayhi wa sallam, praised Allah, and advised and reminded us, then he said: "O people, I am only a human, and the time may be close that the messenger of my Lord will come, so I will respond [i.e. he will pass away]. I am leaving with you the two heavy things, the first is the Quran, which contains guidance and light, whoever adheres to it firmly will be on the guidance, and whoever does not will be misguided. And also my household [family and relatives], take care of my family and relatives [he repeated it three times]."

Abu Bakr (a Companion and the first Caliph) used to say, "Take care of Muhammad, sallallaahu ‘alayhi wa sallam, in terms of his family.

Husayn ibn Sabrah (a Companion) asked Zayd, "Who are his household? Are his wives included amongst them?" He said: "His wives are from his household, but what is meant here is those who are not allowed to accept charity after him." He said: "Who are they?" Zayd answered, "The family of 'Ali, the family of 'Aqeel, the family of Ja'far, and the family of Al-'Abbaas

'Aa'ishah (the wife of the Prophet of Allah, sallallaahu ‘alayhi wa sallam) narrated that Abu Bakr said to 'Ali, "By the One in whose Hand is my soul, I would rather fulfill the ties of kinship towards the relatives of the Prophet of Allah, sallallaahu 'alayhi wa sallam, more so than my own relatives."