Revelational Circumstances of the Qur'an: Surah 42 (Ash-Shura)

This it is which Allah announceth unto His bondmen who believe and do good works. Say (O Muhammad, unto mankind): I ask of you no fee therefor, save lovingkindness among kinsfolk. And whoso scoreth a good deed We add unto its good for him. Lo! Allah is Forgiving, Responsive.

Narrated Tawus
Ibn 'Abbas recited the Quranic Verse:--'Except to be kind to me for my kin-ship to you--" (42.23) Said bin Jubair said, "(The Verse implies) the kinship of Muhammad." Ibn 'Abbas said, "There was not a single house (i.e. sub-tribe) of Quraish but had a kinship to the Prophet and so the above Verse was revealed in this connection, and its interpretation is: 'O Quraish! You should keep good relation between me (i.e. Muhammad) and you."