Musnad Ahmad 834:14

'Abd al-Samad narrated to us, my father narrated to me, Husayn narrated to us, from 'Abdullah ibn Buraydah, 'Abdullah al-Muzani narrated to me, that the Messenger of Allah (may Allah bless him and grant him peace) said: "Do not let the Bedouins overcome you regarding the name of the Maghrib prayer." He said: "And the Bedouins say: It is the 'Isha'."