Al-Hasan ibn Muhammad ibn Sama‘ah narrated from Abdullah ibn Jabalah from ‘Ala’ from Muhammad ibn Muslim: Abu Ja‘far عليه السلام, peace be upon him, said: A man from the people of Madinah said to me: “O Aba Ja‘far, why do I not see you performing voluntary prayers between the adhan and the iqamah as the people do?” I (Imam al-Baqir عليه السلام) said: “When we want to perform voluntary prayers, we perform them at a time other than the time of an obligatory prayer. Once the time for an obligatory prayer enters, there is no voluntary prayer.”