And from him, from Ahmad ibn Muhammad:
He (Imam al-Ridha عليه السلام) said: “The sitting between the Adhan and the Iqamah is for all the prayers, if there is no prayer being performed before the Iqamah.”
Ali Akbar al-Ghaffari
Tahdhīb al-Aḥkām fī Sharḥ al-Muqniʿah, vol. 2, p. 68