Musnad Ahmad 25:420

'Abd al-Wahhab narrated to us, Shu'bah narrated to us, from 'Amr ibn Murrah, from Yahya ibn al-Jazzar, who said: Ibn 'Abbas said: "Two young girls from Banu Hashim passed by, and they came to the Messenger of Allah, peace and blessings of Allah be upon him, while he was praying, and they took hold of his knees, and he did not turn away." Ibn 'Abbas said: "And I and a man from the Ansar passed by the Messenger of Allah, peace and blessings of Allah be upon him, while he was praying, and we were on a donkey, so we came and entered into the prayer."