وَعَنْ عَائِشَةَ رَضِيَ اَللَّهُ عَنْهَا
قَالَتْ: «أَعْتَمَ رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ ذَاتَ لَيْلَةٍ بِالْعَشَاءِ، حَتَّى ذَهَبَ عَامَّةُ اَللَّيْلِ، ثُمَّ خَرَجَ، فَصَلَّى، وَقَالَ: «إِنَّهُ لَوَقْتُهَا لَوْلَا أَنْ أَشُقَّ عَلَى أُمَّتِي»
The Prophet (sallallahu alayhi wa sallam) delayed (the Isha prayer) one night till a great part of the night passed, then he went out and offered the prayer, and said, “This is the proper time for it; were it not that I would impose a burden on my followers.”.
Bulugh al-Maram 187, Book 2, The Book of Prayer, Hadith 8. 1 min read