(466) بَابُ التَّسْلِيمِ بِالْمَعْرِفَةِ وَغَيْرِهَا
'Abdullah ibn 'Amr reported that a man said, "Messenger of Allah,which aspect of Islam is best?" He replied, "Feeding people and greetingthose you know and those you do not know."
Reference: Al-Adab Al-Mufrad 1013
In-book reference: Book 42, Hadith 50
English translation: Book 42, Hadith 1013