Al-Adab Al-Mufrad #324

Asma' bint Yazid reported that the Prophet, may Allah bless him and grant him peace, said, "Shall I tell you who is the best of you?" "Yes,," they replied. He said, "Those who remind you of Allah when you see them." He went on to say, "Shall I tell you who is the worst of you?" "Yes," they replied. He said, "Those who go about slandering, causing mischief between friends in order to separate them, and desiring to lead the innocent into wrong action."