"The Messenger of Allah ﷺ said: 'Between each two Adhans [1] there is a prayer, between each two Adhans there is a prayer, between each two Adhans there is a prayer, for whoever wants to do it." [1]Meaning, between the Adhan and Iqamah. (Using translation from Nasāʾī 681)  

قَالَ رَسُولُ اللهِ ﷺ «بَيْنَ كُلِّ أَذَانَيْنِ صَلَاةٌ بَيْنَ كُلِّ أَذَانَيْنِ صَلَاةٌ بَيْنَ كُلِّ أَذَانَيْنِ صَلَاةٌ لِمَنْ شَاءَ»  

[Machine] I heard Anas ibn Malik say, "The Mu'adhdhin used to call for the Maghrib prayer, and the companions of the Messenger of Allah ﷺ would hasten to perform the two Rak'ahs until the Messenger of Allah ﷺ came out while they were still praying."  

سَمِعْتُ أَنَسَ بْنَ مَالِكٍ يَقُولُ «كَانَ الْمُؤَذِّنُ يُؤَذِّنُ لِصَلَاةِ الْمَغْرِبِ فَيَبْتَدِرُ لُبَابُ أَصْحَابِ رَسُولِ اللهِ ﷺ السَّوَارِيَ يُصَلُّونَ الرَّكْعَتَيْنِ حَتَّى يَخْرُجَ رَسُولُ اللهِ ﷺ وَهُمْ يُصَلُّونَ»