Hadith.1116 - It was narrated from Isma'il ibn Muslim that he asked Imam Jafar ibn Muhammad Al-Sadiq عليه السلام about praying behind a man who denies (or rejects) the decree (Qadar) of Allah سبحانه وتعالى, the Mighty and Majestic.
He (Al-Sadiq) replied: "He should repeat every prayer he performed behind him”.
