Sahih Muslim Book - 6, Hadith - 1783

حَدَّثَنَا يَحْيَى بْنُ يَحْيَى قَالَ قَرَأْتُ عَلَى مَالِكٍ عَنِ ابْنِ شِهَابٍ عَنْ عُرْوَةَ عَنْ عَائِشَةَ أَنَّ رَسُولَ اللَّهِ -صلى الله عليه وسلم- صَلَّى فِى الْمَسْجِدِ ذَاتَ لَيْلَةٍ فَصَلَّى بِصَلاَتِهِ نَاسٌ ثُمَّ صَلَّى مِنَ الْقَابِلَةِ فَكَثُرَ النَّاسُ ثُمَّ اجْتَمَعُوا مِنَ اللَّيْلَةِ الثَّالِثَةِ أَوِ الرَّابِعَةِ فَلَمْ يَخْرُجْ إِلَيْهِمْ رَسُولُ اللَّهِ -صلى الله عليه وسلم- فَلَمَّا أَصْبَحَ قَالَ « قَدْ رَأَيْتُ الَّذِى صَنَعْتُمْ فَلَمْ يَمْنَعْنِى مِنَ الْخُرُوجِ إِلَيْكُمْ إِلاَّ أَنِّى خَشِيتُ أَنْ تُفْرَضَ عَلَيْكُمْ ». قَالَ وَذَلِكَ فِى رَمَضَانَ.

It was narrated from 'Aishah that the Messenger of Allah (s.a.w) prayed in the Masjid one night, and some people followed his prayer. The next night he prayed again, and the numbers of people increased. Then they gathered on the third or fourth night, but the Messenger of Allah (s.a.w) did not come out to them. When morning came, he said: "I saw what you did, and nothing kept me from coming out to you but the fact that I was afraid that it would be made obligatory for you." He said: "And that was in Ramadan."