The Book of Virtue, Good Manners and Joining of the Ties of Relationship (Kitab Al-Birr was-Salat-I-wa'l-Adab)
Muslim :: Book 32 : Hadith 6268
A'isha reported that a person sought permission from Allah's Apostle (may peace be upon him) to see him. He said: Grant him permission. (and also added: ) He is a bad son of his tribe or he is a bad person of his tribe. When he came in he used kind words for him. 'A'isha reported that she said: Allah's Messenger, you said about him what you had to say and then you treated him with kindness. He said: A'isha, verily in the eye of Allah, worst amongst the person in rank on the Day of Resurrection is one whom the people abandon or desert out of the fear of indecency.