Sayyiduna Ibn Abbas (may Allah be pleased with them both) narrated that several trustworthy persons testified before me, and the most trustworthy among them in my view was Sayyiduna Umar (may Allah be pleased with him), that the Prophet (peace and blessings of Allah be upon him) forbade performing prayer after the Fajr prayer until the sun rises high, and after the Asr prayer until the sun sets.
Hadith Referenceاللؤلؤ والمرجان / كتاب صلاة المسافرين وقصرها / 473
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 9 كتاب مواقيت الصلاة: 30 باب الصلاة بعد الفجر حتى ترتفع الشمس»
Brief Explanation
There are certain times during the day and night in which performing prayer (salah) is disliked (makruh): at sunrise, exactly at midday (when the sun is at its zenith), after the ‘Asr prayer until sunset, and after the Fajr prayer until sunrise. However, if an obligatory (fard) prayer has been missed (qada), it is permissible to perform it during these times. Likewise, if the Sunnah prayers of Fajr could not be performed before the obligatory Fajr prayer, they may also be performed after the Fajr obligatory prayer. (Raaz)