كتاب الْمَسَاجِدِ وَمَوَاضِعِ الصَّلاَةِ
5  
The Book of Mosques and Places of Prayer
(39)
Chapter: The time of `Isha and delaying it
(39)
باب وَقْتِ الْعِشَاءِ وَتَأْخِيرِهَا ‏
Sahih Muslim 641

Abu Musa reported:

I and my companions who had sailed along with me in the boat landed with me in the valley of Buthan while the Messenger of Allah (ﷺ) was staying in Medina. A party of people amongst them went to the Messenger of Allah (ﷺ) every night at the time of the 'Isya' prayer turn by turn. Abu Musa said: (One night) we (I and my companions) went to the Messenger of Allah (ﷺ) and he was occupied in some matter till there was a delay in prayer so much so that it was the middle of the night. The Messenger of Allah (ﷺ) then came out and led them (Musa's companions) in prayer. And when he had observed his prayer he said to the audience present: Take it easy, I am going to give you information and glad tidings that it is the blessing of Allah upon you for there is none among the people, except you, who prays at this hour (of the night), or he said: None except you observed prayer at this. (late) hour. He (i. e. the narrator) said: I am not sure which of these two sentences he actually uttered. Abu Musa, said: We came back happy for what we heard from the Messenger of Allah (ﷺ).
وَحَدَّثَنَا أَبُو عَامِرٍ الأَشْعَرِيُّ، وَأَبُو كُرَيْبٍ قَالاَ حَدَّثَنَا أَبُو أُسَامَةَ، عَنْ بُرَيْدٍ، عَنْ أَبِي بُرْدَةَ، عَنْ أَبِي مُوسَى، قَالَ كُنْتُ أَنَا وَأَصْحَابِي الَّذِينَ، قَدِمُوا مَعِي فِي السَّفِينَةِ نُزُولاً فِي بَقِيعِ بُطْحَانَ وَرَسُولُ اللَّهِ صلى الله عليه وسلم بِالْمَدِينَةِ فَكَانَ يَتَنَاوَبُ رَسُولَ اللَّهِ صلى الله عليه وسلم عِنْدَ صَلاَةِ الْعِشَاءِ كُلَّ لَيْلَةٍ نَفَرٌ مِنْهُمْ قَالَ أَبُو مُوسَى فَوَافَقْنَا رَسُولَ اللَّهِ صلى الله عليه وسلم أَنَا وَأَصْحَابِي وَلَهُ بَعْضُ الشُّغُلِ فِي أَمْرِهِ حَتَّى أَعْتَمَ بِالصَّلاَةِ حَتَّى ابْهَارَّ اللَّيْلُ ثُمَّ خَرَجَ رَسُولُ اللَّهِ صلى الله عليه وسلم فَصَلَّى بِهِمْ فَلَمَّا قَضَى صَلاَتَهُ قَالَ لِمَنْ حَضَرَهُ ‏"‏ عَلَى رِسْلِكُمْ أُعْلِمُكُمْ وَأَبْشِرُوا أَنَّ مِنْ نِعْمَةِ اللَّهِ عَلَيْكُمْ أَنَّهُ لَيْسَ مِنَ النَّاسِ أَحَدٌ يُصَلِّي هَذِهِ السَّاعَةَ غَيْرُكُمْ ‏"‏ ‏.‏ أَوْ قَالَ ‏"‏ مَا صَلَّى هَذِهِ السَّاعَةَ أَحَدٌ غَيْرُكُمْ ‏"‏ ‏.‏ لاَ نَدْرِي أَىَّ الْكَلِمَتَيْنِ قَالَ قَالَ أَبُو مُوسَى فَرَجَعْنَا فَرِحِينَ بِمَا سَمِعْنَا مِنْ رَسُولِ اللَّهِ صلى الله عليه وسلم ‏.‏
Reference : Sahih Muslim 641
In-book reference : Book 5, Hadith 284
USC-MSA web (English) reference : Book 4, Hadith 1339
  (deprecated numbering scheme)