1538 — Ubayd Allah ibn Ahmad informed us: Ahmad ibn al-Husayn informed us. He said: Abdullah ibn Ahmad narrated to us. He said: My father narrated to us. He said: Ya‘qub ibn Ibrahim narrated to us. He said: My father narrated to us, from Muhammad ibn Ishaq. He said: Aban ibn Salih narrated to us, from Mujahid Abu al-Hajjaj, from Jabir ibn Abdullah, who said: I asked him, “During the time of the Messenger of Allah, what deed distinguished disbelief from faith in your view?” He replied, “The prayer.”