Sunan Ibn Majah 691
سنن ابن ماجه#691SahihIt was narrated that Abu Hurairah said:"The Messenger of Allah said: 'Were it not that it would be too difficult for my Ummah, I would have delayed the 'Isha' prayer until one third or one half of the night had passed
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Al-AlbaniSahih
Muhammad Fouad Abd al-BaqiSahih
Shuaib Al ArnautHasan Sahih
Zubair Ali ZaiIsnaad Sahih
In-book reference: 2:25