And the evidence that silence is not contrary to speech, and it is not permissible to use silence as proof against speech as some of those who claim knowledge imagine, is that if it were permissible to use silence as proof against speech, then in his saying: "There is no prayer after Fajr until the sun rises," there would be permission for prayer when the sun rises, even if the one praying intends with his prayer the rising of the sun.
Sayyiduna Ibn Umar (may Allah be pleased with them both) narrates that the Messenger (peace and blessings of Allah be upon him) said: "Do not intend or aim to perform your prayer at the time of sunrise or sunset. For it sets between the two horns of Satan." Also, the Messenger of Allah (peace and blessings of Allah be upon him) said: "When the edge of the sun appears, refrain from prayer until it becomes fully risen. And when the edge of the sun sets, refrain from prayer until it is completely set." This is the narration of Bundar, and the wording of the narration from Abu Kuraib is: "Indeed, it rises between the two horns of Satan."
Hadith Referenceصحيح ابن خزيمه / جماع أبواب الأوقات التى ينهى عن صلاة التطوع فيهن / 1273