And from him, from Safwan from al-Ala from Muhammad ibn Muslim from one of the two (Imams عليه السلام), peace be upon them, who said:
I asked Imam عليه السلام about the prayer on the Day of Fitr and the Day of Adha. Imam عليه السلام said: “There is no prayer except with a (just) imam.”
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 3, p. 140