Chapter on the Detailed Explanation of Prayer, Including the Obligatory and Recommended, and What is Permissible and Not Permissible.

Al-Tatari, from Abdullah ibn Jabalah, from al-’Alaʾ ibn Razin, from Muhammad ibn Muslim: (Imam) Abu Ja’far عليه السلام said: “A man from the people of Madinah said to me, ‘O Aba Ja’far, why do I not see you performing supererogatory (‘tatawwu’) prayers between the adhan and the iqamah as the people do?’” He (Imam al-Baqir عليه السلام) said: "So I replied, 'When we want to perform supererogatory prayers, we do so outside the time of the obligatory prayer. Once the time of the obligatory prayer enters, there is no supererogatory prayer (to be performed).'"