Musannaf Ibn Abi Shayba 3:4943

Abu Bakr narrated to us, he said: Sufyan ibn ‘Uyaynah narrated to us, from Damrah ibn Sa’id, who heard Abu Sa’id saying: The Messenger of Allah (may Allah bless him and grant him peace) forbade prayer after the ‘Asr [prayer] until the sunset, and after the Fajr [prayer] until the sunrise.