Sunan Ibn Majah 704
سنن ابن ماجه#704SahihIt was narrated that Ibn 'Umar said:"I heard the Messenger of Allah say: 'Do not let the Bedouin make you change the name of your prayer. It is the 'Isha', and they bring their camels in and milk them at nightfall
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 ArnautSahih
Zubair Ali ZaiSahih Muslim
In-book reference: 2:38