The Messenger of Allah ﷺ led us in the night prayer, the one people call al-atamah, then he turned to face us and said, "Do you see this night of yours? At the end of one hundred years from it, no one who is on the face of the earth today will remain."
صلى لنا رسول الله ﷺ ليلة الصلاة العشاء- وهي التي يدعو الناس العتمة- ثم انصرف، فأقبل علينا فقال: أرأيتم ليلتكم هذه، فإن رأس مائة سنة منها لا يبقى ممن هو على ظهر الأرض أحد.
Bukhari narrated it in "Prayer Times" (564) and Muslim in "Virtues of the Companions" (2537), both through Zuhri. Salim said, "Abdullah informed me," then he related it. The wording given is Bukhari's.Reconciling these hadiths can be approached in several ways.One is to clarify that calling Isha "atamah" is permissible, so the prohibition here is meant to discourage rather than to forbid.Another is that people were being addressed with what they were already familiar with.Another is that they were being taught to abandon what was not fitting.Another is so that they would not mistakenly think it referred to Maghrib, since among them the term "Isha" was sometimes used to mean Maghrib.Another is that perhaps it was the narrators themselves who took the liberty of calling Isha "atamah."The conclusion is that the name given by Islam to this prayer is "Isha," so it is not preferable to depart from it in favor of "atamah," lest the sunnah be overtaken by pre-Islamic custom. Nevertheless, using the term is not forbidden, as shown by the Prophet'sﷺ own use of it and the companions' use of it after him.