It was narrated that ‘Abdullah bin Mughaffal said:“The Prophet of Allah (ﷺ) said: ‘Between every two Adhans there is a prayer.’ He said it three times, and on the third time he said, ‘For those who wish.’”*
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا أَبُو أُسَامَةَ، وَوَكِيعٌ، عَنْ كَهْمَسٍ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ بُرَيْدَةَ، عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ، قَالَ قَالَ نَبِيُّ اللَّهِ ـ صلى الله عليه وسلم ـ " بَيْنَ كُلِّ أَذَانَيْنِ صَلاَةٌ " . قَالَهَا ثَلاَثًا قَالَ فِي الثَّالِثَةِ " لِمَنْ شَاءَ " .
IbnMaja
Establishing the Prayer and the Sunnah Regarding Them • Hadith 1162