“I once asked abu Ja’far (a.s.), ‘Certain people have narrated that ’Amir al-Mu’minin performed four Rak‘at after Friday without any interval of saying Salam (the phrase of offering greeting of peace) in between. He (the Imam) said, ‘O Zurarah, ’Amir al-Mu’minin performed Salah (prayer) behind a sinful one. When he said Salam (the phrase of offering greeting of peace) and moved away ’Amir al-Mu’minin stood up, performed four Rak‘at without interval in between by means of saying Salam (the phrase of offering greeting of peace). A man from his side then said, ‘O abu al- Hassan you performed four Rak‘at without interval in between.’ He (’Amir al-Mu’minin)) said, ‘They were four similar Rak‘at’ and remained quiet. By Allah, he did not understand what he said.’”