Musnad Ahmad 27:880

I read to Abd al-Rahman ibn Mahdi: Malik, from Abdullah ibn Dinar, from Ibn Umar, "That the Messenger of Allah, peace and blessings of Allah be upon him, used to—and there was in the copy which I read to Abd al-Rahman 'Nafi', so he changed it and said: Abdullah ibn Dinar—he used to come to Quba riding and walking."