The word فجر صبح سحر mentioned in Quran. Quranic Verses about Dawn.
The word Dawn فجر صبح سحر mentioned 12 times in Quran in 11 verses.
وَكُلُوا وَاشْرَبُوا حَتَّىٰ يَتَبَيَّنَ لَكُمُ الْخَيْطُ الْأَبْيَضُ مِنَ الْخَيْطِ الْأَسْوَدِ مِنَ الْفَجْرِ
It has been made permissible for you the night preceding fasting to go to your wives [for sexual relations]. They are clothing for you and you are clothing for them. Allah knows that you used to deceive yourselves, so He accepted your repentance and forgave you. So now, have relations with them and seek that which Allah has decreed for you. And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the sunset. And do not have relations with them as long as you are staying for worship in the mosques. These are the limits [set by] Allah , so do not approach them. Thus does Allah make clear His ordinances to the people that they may become righteous.
الصَّابِرِينَ وَالصَّادِقِينَ وَالْقَانِتِينَ وَالْمُنْفِقِينَ وَالْمُسْتَغْفِرِينَ بِالْأَسْحَارِ
The patient, the true, the obedient, those who spend [in the way of Allah], and those who seek forgiveness before dawn.
فَالِقُ الْإِصْبَاحِ وَجَعَلَ اللَّيْلَ سَكَنًا
[He is] the cleaver of daybreak and has made the night for rest and the sun and moon for calculation. That is the determination of the Exalted in Might, the Knowing.
أَقِمِ الصَّلَاةَ لِدُلُوكِ الشَّمْسِ إِلَىٰ غَسَقِ اللَّيْلِ وَقُرْآنَ الْفَجْرِ ۖ إِنَّ قُرْآنَ الْفَجْرِ كَانَ مَشْهُودًا
Establish prayer at the decline of the sun [from its meridian] until the darkness of the night and [also] the Qur’an of dawn. Indeed, the recitation of dawn is ever witnessed.
مِنْ قَبْلِ صَ