Chapter on the Rulings of Congregational Prayer (the Minimum Number for Congregational Prayer, the Description of the Imam, Who Is to Be Followed and Who Is Not to Be Followed, Recitation Behind Both of Them, the Rulings of Those Led in Prayer, and Other Such Rulings Related to It)

Ahmad ibn Muhammad ibn Isa narrated from al-Hasan ibn Ali ibn Faddal, from Abdillah ibn Bukayr; and al-Husayn ibn Said narrated from Fadalah ibn Ayyub, from Abdillah ibn Bukayr, who said: Hamzah ibn Humran asked Aba Abdillah عليه السلام, peace be upon him, about a man who led us in prayer during travel while he was in a state of janabah (major ritual impurity), and he knew (of his condition) while we did not know. Imam عليه السلام said: “There is no problem.” (meaning those who prayed behind him are not required to repeat it)