Sunan an-Nasa'i 533
سنن النسائي#533SahihIt was narrated that Jabir bin Samurah said:"The Messenger of Allah (ﷺ) used to delay the later 'Isha'."[1] [1] It is described as the later 'Isha' prayer because the Maghrib prayer is sometimes called 'Isha' prayer, but it is the first 'Isha'. Some scholars are of the opinion that it is disliked to call Maghrib 'Isha' without qualifying it as the first 'Isha'. See Fath Al-Bari
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Abu GhuddahSahih
Al-AlbaniSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 6:40