Sunan an-Nasai 15271
In-book no 535أَخْبَرَنَا قُتَيْبَةُ، قَالَ حَدَّثَنَا أَبُو الأَحْوَصِ، عَنْ سِمَاكٍ، عَنْ جَابِرِ بْنِ سَمُرَةَ، قَالَ كَانَ رَسُولُ اللَّهِ صلى الله عليه وسلم يُؤَخِّرُ الْعِشَاءَ الآخِرَةَ .
It was narrated that Jabir bin Samurah said: "The Messenger of Allah (ﷺ) used to delay the later 'Isha'." 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.