Musnad Ahmad 2:273

Muhammad ibn Ja‘far narrated to us, Shu‘bah narrated to us, from Qatadah, who said: I heard Rafi‘ Abu al-‘Aliyah narrating from Ibn ‘Abbas: Some men narrated to me—Shu‘bah said: I think he said: from the companions of the Prophet, may Allah bless him and grant him peace—and the most pleasing of them to me was ‘Umar ibn al-Khattab—that the Messenger of Allah, may Allah bless him and grant him peace, forbade prayer at two times: after the ‘Asr until the sun sets, and after the Subh until it rises.