It is narrated from Sayyiduna Abdullah bin Abbas (may Allah be pleased with them both): the Prophet (peace and blessings be upon him) said: "Shall I not tell you about the worst of you?" The people said: "Yes, O Messenger of Allah, if you wish." The Prophet (peace and blessings be upon him) said: "The worst of you are those who camp alone, flog their slaves and withhold their gifts." The Prophet (peace and blessings be upon him) asked: "Shall I not tell you about someone even worse than that?" The people said: "O Messenger of Allah, yes, if you wish." The Prophet (peace and blessings be upon him) said: "The one who hates people and whom people hate." Then the Prophet (peace and blessings be upon him) said: "Shall I not tell you about someone even worse than that?" The people said: "Yes, O Messenger of Allah, if you wish." The Prophet (peace and blessings be upon him) said: "Those who do not overlook a slip, do not accept an excuse and do not forgive a sin." The Prophet (peace and blessings be upon him) said: "Shall I not tell you about someone even worse than that?" The people said: "Yes, O Messenger of Allah!" The Prophet (peace and blessings be upon him) said: "The one from whom no good is hoped and from whose evil (people do) not feel safe."
Al-Tabarani recorded it; its chain contains a narrator, Anbas bin Maymun, who is matruk (abandoned).