وَعَنْ اِبْنِ عَبَّاسٍ رَضِيَ اَللَّهُ عَنْهُمَا
قَالَ: قَالَ رَسُولُ اَللَّهِ صَلَّى اللَّهُ عَلَيْهِ وَسَلَّمَ -«اَلْفَجْرُ فَجْرَانِ: فَجْرٌ يُحَرِّمُ اَلطَّعَامَ وَتَحِلُّ فِيهِ اَلصَّلَاةُ، وَفَجْرٌ تَحْرُمُ فِيهِ اَلصَّلَاةُ (أَيْ: صَلَاةُ اَلصُّبْحِ) وَيَحِلَّ فِيهِ اَلطَّعَامُ»
The Messenger of Allah (sallallahu alayhi wa sallam) said that, “Dawn is of two types; the dawn in which eating is forbidden (for the fasting person) and prayer is permitted and the dawn in which prayer is forbidden i.e. the morning prayer and eating is permitted.”.
Bulugh al-Maram 200, Book 2, The Book of Prayer, Hadith 21. 1 min read