The oath of fifty people when there is positive loth is intentional murder. Qassama has been suspected by the opponents of Islam and some Shia jurists due to the progress of science and the discovery of modern ways of proof. The consensus opinion of Shia jurisprudence in the mentioned issue confirms the validity of Qassama, and the Islamic Penal Code has also mentioned the validity of Qassama in the penal code, following Shia jurisprudence. However, the legislator has chosen an opinion in the new law in a part of the mentioned issue, which has caused the illusion of the invalidity of Qassama. The sub-problem mentioned is that if fifty oaths are not taken by fifty people on behalf of the claimant; There are two jurisprudential opinions regarding the permissibility and impermissibility of repeating Qassama. In the new law, the legislator, unlike the previous laws, is of the opinion that it is not permissible to repeat Qassama, which is an unpopular theory. is chosen The most important contemporary jurists believe in the unpopular theory of the Supreme Leader of the Islamic Revolution. The choice of the unpopular opinion, in addition to the illusion of invalidity of the principle of Qassama, has caused the question of why the legislator left the opinion of the famous jurist. Due to the lack of independent research on the problem and its importance, the present article intends to answer the aforementioned dual questions by using the analytical descriptive method. The present article has come to the conclusion that the legislator's approach is flawed due to the existence of valid evidence on the unpopular theory and the distortion of the evidence of the famous theory. Also, the principle of Qassam validity is defensible in terms of Islamic jurisprudence and law.