Abdullah bin Umar (may Allah be pleased with them) narrates that the Prophet (ﷺ) said: "Let not the Bedouins overpower you regarding the name of your prayer; its name is 'Isha.' These people call it 'Atamah' because they milk their she-camels in the darkness."
Hadith Referenceمسند الإمام الشافعي / كتاب الصلاة / 148
Hadith Takhrijاخرجه مسلم ، المساجد، باب وقت العشاء وتأخيرها (644).