It is narrated from Sayyiduna Umar (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) used to say: "No prayer should be performed after the Fajr prayer until the sun rises, and no voluntary prayer should be performed after the Asr prayer until the sun sets."
Hadith Referenceمسند احمد / مسند الخلفاء الراشدين / 118
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد ضيعف لانقطاعه، عمرو بن شعيب لم يدرك عبدالله بن عمرو بن العاص