حَدَّثَنَا مُحَمَّدُ بْنُ عِيسَى، حَدَّثَنَا أَبُو مُعَاوِيَةَ، عَنْ هِلاَلِ بْنِ مَيْمُونٍ، عَنْ عَطَاءِ بْنِ يَزِيدَ، عَنْ أَبِي سَعِيدٍ الْخُدْرِيِّ، قَالَ قَالَ رَسُولُ اللَّهِ صلى الله عليه وسلم ‏"‏ الصَّلاَةُ فِي جَمَاعَةٍ تَعْدِلُ خَمْسًا وَعِشْرِينَ صَلاَةً فَإِذَا صَلاَّهَا فِي فَلاَةٍ فَأَتَمَّ رُكُوعَهَا وَسُجُودَهَا بَلَغَتْ خَمْسِينَ صَلاَةً ‏"‏ ‏.‏ قَالَ أَبُو دَاوُدَ قَالَ عَبْدُ الْوَاحِدِ بْنُ زِيَادٍ فِي الْحَدِيثِ ‏"‏ صَلاَةُ الرَّجُلِ فِي الْفَلاَةِ تُضَاعَفُ عَلَى صَلاَتِهِ فِي الْجَمَاعَةِ ‏"‏ ‏.‏ وَسَاقَ الْحَدِيثَ ‏.‏

Narrated AbuSa'id al-Khudri: Prayer in congregation is equivalent to twenty-five prayers (offered alone). If he prays in a jungle, and performs its bowing and prostrations perfectly, it becomes equivalent to fifty prayers (in respect of reward). Abu Dawud said: 'Abd al-Walid b. Ziyad narrated in his version of this tradition: "Prayer said by a single person in a jungle is more excellent by multiplied degrees than prayer said in congregation." Translation Not Available

Book Ref: Sunan Abi Dawud Book 2 Hadith 560
Web Ref:  Sunan Abi Dawud Book 2 Hadith 560