Musnad Ahmad 1153:1236

Abu Amir and Surayj—meaning Ibn al-Nu‘man—narrated to us, they said: Fulayh narrated to us, from ‘Abd Allah ibn ‘Abd al-Rahman ibn Ma‘mar, from Abu Yunus, the freed slave of ‘A’ishah, from ‘A’ishah, who said: A man asked for permission to enter upon the Prophet, may Allah bless him and grant him peace, so he said: "An evil son of the clan." When he entered, the Messenger of Allah, may Allah bless him and grant him peace, smiled at him and was open with him. Then he left. Another man asked for permission to enter, so the Prophet, may Allah bless him and grant him peace, said: "A good son of the clan." When he entered, he was not as open with him as he was with the other, nor did he smile at him as he had smiled at the other. When he left, I said: "O Messenger of Allah, such-and-such a person asked for permission, and you said to him what you said, then you smiled at him and were open with him. And you said to such-and-such a person what you said, yet I did not see you treat him as you treated the other." He said: "O ‘A’ishah, indeed, among the worst of people is the one whom people avoid out of fear of his obscenity."