Sunan Ibn Majah, Volume 1, Book 2, Hadith 690 (DarusSalam) ⓘ
It was narrated from Abu Hurairah that: The Messenger of Allah said: "Were it not that it would be too difficult for my Ummah, I would have commanded them to delay the 'Isha'."
حَدَّثَنَا هِشَامُ بْنُ عَمَّارٍ، حَدَّثَنَا سُفْيَانُ بْنُ عُيَيْنَةَ، عَنْ أَبِي الزِّنَادِ، عَنِ الأَعْرَجِ، عَنْ أَبِي هُرَيْرَةَ، . أَنَّ رَسُولَ اللَّهِ ـ صلى الله عليه وسلم ـ قَالَ " لَوْلاَ أَنْ أَشُقَّ عَلَى أُمَّتِي لأَمَرْتُهُمْ بِتَأْخِيرِ الْعِشَاءِ " .
also referenced under: Hadith 690 (Reference) & Book 2, Hadith 24 (In-Book)