Consider the following verse...

Other dates are also recorded. The need for it became apparent when the number of Muslims became so many that it was hard for them all to know when to pray. They talked to each other and decided to establish a sign indicating that it is time to pray. Some suggested to ring a bell but the Prophet did not agree since this was a Christian practice. Some suggested the use of a horn but the Prophet did not agree since this was a Jewish practice.

Some suggested playing on the tambourine but the Prophet said that this was a Roman practice. Others suggested using fire but the Prophet said that this was a practice of the Magians.[^2] Some suggested raising a flag, but the Prophet did not say anything. Therefore, they did not settle on anything specific. Gabriel descended when the Prophet was in Ali’s house and revealed the decree for the call to prayer.

Sadooq narrated in Man La Yahzuruhu al-Faqih: “Mansoor ibn Hazim quoted on the authority of Imam Sadiq : Gabriel descended to the Prophet of God when he was sleeping in Ali’s house. Gabriel recited the ‘Azan’ and the ‘Iqamah.’ Then the Prophet said: O’ Ali! Did you hear that? He said: “O’ Prophet of God!

Yes.” Then the Prophet said: “Did you memorize it?” Imam Ali said: “Yes.” Then the Prophet said: “Then teach it to Bilal.” Then Ali taught it to Bilal.[^3] The Jurisprudents’ Rule on the Call to Prayer It is recommended for men and women to say the ‘Azan’ and ‘Iqamah’ before they pray. It has been quoted on the authority of Al-Mashoor, as quoted by many others that it is recommended to say the ‘Azan’ and ‘Iqamah’.

It is quoted in the books Al-Jomal and its commentary, Al-Moqna’eh, Al-Nahayat, Al-Mabsoot, Al-Waseeleh, Al-Mohaz’zab, and Mofid’s Akham Al-Nisaa that it is obligatory for men to say the ‘Azan’ and ‘Iqamah’ in congregational prayers.