عَنْ عَائِشَةَ أُمّ الْمُؤْمِنِينَ ـ رضى الله عنها أَنَّ رَسُولَ اللہِ صلّى اللہُ عليه وسلم صَلَّى ذَاتَ لَيْلَةٍ فِي الْمَسْجِدِ فَصَلَّى بِصَلاَتِهِ نَاسٌ، ثُمَّ صَلَّى مِنَ الْقَابِلَةِ فَكَثُرَ النَّاسُ، ثُمَّ اجْتَمَعُوا مِنَ اللَّيْلَةِ الثَّالِثَةِ أَوِ الرَّابِعَةِ، فَلَمْ يَخْرُجْ إِلَيْهِمْ رَسُولُ اللہِ صلى الله عليه وسلم، فَلَمَّا أَصْبَحَ قَالَ: قَدْ رَأَيْتُ الَّذِي صَنَعْتُمْ وَلَمْ يَمْنَعْنِي مِنَ الْخُرُوجِ إِلَيْكُمْ إِلاَّ أَنِّي خَشِيتُ أَنْ تُفْرَضَ عَلَيْكُمْ؛ وَذَلِكَ فِي رَمَضَانَ.
Hazrat Umm-ul-Momineen Aishahra narrated that Allah’s Messengersa prayed one night in the mosque, and people joined him. Then, on a subsequent night, he prayed again, and more people came. On the third or fourth night, the people again gathered, but Allah’s Messengersa did not go out to them. When morning came, he said, “I saw what you were doing. Only my fear that this prayer might become obligatory upon you prevented me from coming out.” This took place during Ramadan.
(Sahih al-Bukhari, Kitab at-tahajjud, Bab tahrisi n-nabiyyisa salati l-layli wa n-nawafili min ghayri ijab, Hadith 1129)