أَخْبَرَنَا عُبَيْدُ اللَّهِ بْنُ سَعِيدٍ، عَنْ يَحْيَى، عَنْ كَهْمَسٍ، قَالَ حَدَّثَنَا عَبْدُ اللَّهِ بْنُ بُرَيْدَةَ، عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ بَيْنَ كُلِّ أَذَانَيْنِ صَلاَةٌ بَيْنَ كُلِّ أَذَانَيْنِ صَلاَةٌ بَيْنَ كُلِّ أَذَانَيْنِ صَلاَةٌ لِمَنْ شَاءَ ‏"‏ ‏.‏

It was narrated that 'Abdullah bin Mughaffal said: "The Messenger of Allah (PBUH) 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. Translation Not Available

Book Ref: Sunan An Nisai Book 7 Hadith 689
Web Ref:  Sunan An Nisai Vol 1 Book 7 Hadith 682