Musnad Ahmad 1153:520

Khalaf ibn al-Walid narrated to us, he said: 'Abbad ibn 'Abbad narrated to us, from Muhammad ibn 'Amr, from Yahya ibn 'Abd al-Rahman, from 'Aisha, she said: "The Abyssinians played in the presence of the Prophet, may Allah bless him and grant him peace, in the mosque. So I came to watch, and he began to lower his shoulders for me so that I could look at them."