صَحِيحُ مُسْلِمٍ
Sahih Muslim 838 b
The Book of Prayer - Travellers
Between every two calls, there is a prayer
وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَبْدُ الأَعْلَى، عَنِ الْجُرَيْرِيِّ، عَنْ عَبْدِ اللَّهِ، بْنِ بُرَيْدَةَ عَنْ عَبْدِ اللَّهِ بْنِ مُغَفَّلٍ، عَنِ النَّبِيِّ صلى الله عليه وسلم . مِثْلَهُ إِلاَّ أَنَّهُ قَالَ فِي الرَّابِعَةِ لِمَنْ شَاءَ .
This hadith has been narrated by Abdullah b. Mughaffal by another chain of transmitters, but with this variation that he (the Prophet) said at the fourth time: " He who wishes (may do to)."
Sahih Muslim, 838 bSahihصحيح