Musnad Ahmad 2:189

'Affan narrated to us, Hammam narrated to us, Qatadah narrated to us, Abu al-'Aliyah narrated to us, from Ibn 'Abbas: Men who are pleasing to me narrated to me, among them 'Umar—and 'Affan said once: Men who are pleasing to me testified before me, and the most pleasing of them to me is 'Umar—that the Messenger of Allah (peace and blessings of Allah be upon him) said: "There is no prayer after two prayers: after the dawn (subh) until the sun rises, and after the afternoon (asr) until the sun sets."