Al-Kāfi - The Book of Prayer

Chapter: Commencement of Adhan, Iqamah, and the Excellence of Reading them َدُ بْنُ إِدْرِيسَ عَنْ أَحْ٠َّدٍ عَنِ الْحُسَيْنِ بْنِ سَعِيدٍ عَنِ ابْنِ أَبِي نَجْرَانَ عَنْ صَفْوَانَ الْجَ٠ِعْتُ أَبَا عَبْدِ الله (عَلَيْهِ الْسَّلا٠) يَقُولُ الأذَانُ ٠َثْنَى وَالإِقَا٠4.

Ahmad ibn Idris has narrated from Ahmad ibn Muhammad from al-Husayn ibn Sa‘id from ibn abu Najran from Safwan al-Jammal who has said the following: “I once heard abu ‘Abd Allah (a.s.), say, ‘Adhan is twice and twice and ‘Iqamah is twice and twice.’” صحيح - Allamah Baqir al-Majlisi (Mirʾāt al-ʿUqūl fī Sharḥ Akhbār Āl al-Rasūl (15/82))