Sahih al-Bukhari 1921
Book 30: Fasting · Narrated by Anas
Arabic
حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا هِشَامٌ، حَدَّثَنَا قَتَادَةُ، عَنْ أَنَسٍ، عَنْ زَيْدِ بْنِ ثَابِتٍ ـ رضى الله عنه ـ قَالَ تَسَحَّرْنَا مَعَ النَّبِيِّ صلى الله عليه وسلم ثُمَّ قَامَ إِلَى الصَّلاَةِ. قُلْتُ كَمْ كَانَ بَيْنَ الأَذَانِ وَالسَّحُورِ قَالَ قَدْرُ خَمْسِينَ آيَةً.
English translation
Narrated Anas:Zaid bin Thabit said, "We took the Suhur with the Prophet (ﷺ) . Then he stood for the prayer." I asked, "What was the interval between the Suhur and the Adhan?" He replied, "The interval was sufficient to recite fifty verses of the Qur'an
Reference: Sahih al-Bukhari 1921, Book of Fasting. English translation by Dr. Muhammad Muhsin Khan.