Musnad Abu Ya'la al-Mawsili 115:207

Zuhayr ibn Harb narrated to us, Wahb ibn Jarir narrated to us, my father narrated to us, from Qatadah, from Anas: That the Prophet, may Allah bless him and grant him peace, was cupped on the two sides of the neck (al-akhda'ayn) and the upper back (al-kahil).