Chapter on Rulings on Forgetfulness (Sahw) in Prayer and What Requires Repeating of Prayer

And from him, from Muhammad bin Nusayr, who said: Muhammad bin Isa narrated to us, from Ibn Abi Umayr, from Hammad, from al-Halabi, from Abu Abdillah عليه السلام: And I asked Him عليه السلام about a man who led a group in prayer for ‘Asr, then remembered while he was praying with them that he had not yet prayed Dhuhr. Imam عليه السلام said: “Then he should count it as the Dhuhr which he had missed, and begin ‘Asr anew. As for the people, they have completed their prayer."