It is narrated from Sayyiduna Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "These characters are (granted) by Allah. So when Allah intends good for someone, He grants him good character, and when He intends evil for someone, He gives him bad character."
Imam al-Tabarani (may Allah have mercy on him) said: "Only Maslamah bin Ali narrated this hadith from Muhammad bin Ajlan, and Imran bin Harun is alone in narrating it from him."