It is narrated from Ubaydullah ibn Ali Al-Halabi, who said: Abu Abdullah عليه السلام was asked about the categories of witnesses whose testimony is to be rejected. Imam عليه السلام replied: "The one suspected (Al-Zaneen), the accused (Al-Muttaham), and the adversary (Al-Khasm)." I said: "What about the immoral (Al-Fasiq) and the dishonest (Al-Kha'in)?" Imam عليه السلام said: "These fall under the category of the suspected (Al-Zaneen)."