Chapter on the Adhan and the Iqamah

From him, from Muhammad ibn Al-Husayn, from Ja'far ibn Bashir, from Hammad ibn Uthman, from Ubayd ibn Zurarah, from his father who said: I asked Abu Ja’far عليه السلام, peace be upon him, about a man who forgot the Adhan and the Iqamah until he had entered into the prayer. Imam عليه السلام said: "He should continue with his prayer, for the Adhan is a Sunnah."