It is narrated from Sayyiduna Safwan bin al-Mu'attal al-Sulami (may Allah be pleased with him) that he asked the Messenger of Allah (peace and blessings be upon him): "O Prophet of Allah! I am asking you about a matter that you know and of which I am ignorant." He (peace and blessings be upon him) asked: "What is it?" He said: "Is there any time among the hours of the night and day in which praying is disliked?" He (peace and blessings be upon him) said: "When you have prayed the dawn prayer, refrain from prayer until the sun rises, for it rises between the two horns of Satan. Then (after it has risen) pray, for the prayer is accepted, until the sun is straight above your head like a spear. When it is above your head like a spear, leave off prayer, for that is the time when Hell is stoked and its gates are opened, until the sun passes the meridian. When the sun has passed the meridian, the prayer is attended (by the angels) and accepted until you pray Asr. Then refrain from prayer until the sun sets." This hadith has an authentic (sahih) chain of narration, but the two Shaykhs (Bukhari and Muslim) did not record it.