When the muadhin gave the call to prayer, the companions of the Messenger of Allah ﷺ would rush to the pillars of the mosque and remain there praying, meaning the two units of prayer before Maghrib, until the Messenger of Allah ﷺ came out while they were still doing so. There was only a short interval between the call to prayer and the iqamah.
حدثنا محمد بن جعفر حدثنا شعبة قال سمعت عمرو بن عامر الأنصاري
كان المؤذن إذا أذن قام أصحاب رسول الله ﷺ يبتدرون السواري حتى يخرج رسول الله ﷺ وهم كذلك يعني الركعتين قبل المغرب ولم يكن بين الأذان والإقامة إلا قريب
Its isnad is sahih. Bukhari narrated the hadith with this wording, 2/106 no. 625 (Fath), in the Book of Adhan, chapter on how long is between the adhan and the iqamah. Nasai also narrated it, 2/28, in the Book of Adhan, chapter on prayer between the adhan and the iqamah. Darimi narrated it as well, 1/336, Dar al-Fikr edition, in the Book of Prayer, chapter on the two rakahs before Maghrib.