"When the Mu'adh-dhin pronounced the Adhan, some of the companions of the Prophet (ﷺ) would
proceed to the pillars of the mosque (for the prayer) till the Prophet (ﷺ) arrived and in this way they used
to pray two rak`at before the Maghrib prayer. There used to be a little time between the Adhan and the
Iqama." Shu`ba said, "There used to be a very short interval between the two (Adhan and Iqama).
Sahih al-Bukhari Book 10, Hadith 22