Interval between the Sahur and Salat-ul-Fajr

Narrated Anas:

Zaid bin Thabit said, "We took the Suhur with the Prophet . 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 Quran."

حَدَّثَنَا مُسْلِمُ بْنُ إِبْرَاهِيمَ، حَدَّثَنَا هِشَامٌ، حَدَّثَنَا قَتَادَةُ، عَنْ أَنَسٍ، عَنْ زَيْدِ بْنِ ثَابِتٍ ـ رضى الله عنه ـ قَالَ تَسَحَّرْنَا مَعَ النَّبِيِّ ﷺ ثُمَّ قَامَ إِلَى الصَّلاَةِ. قُلْتُ كَمْ كَانَ بَيْنَ الأَذَانِ وَالسَّحُورِ قَالَ قَدْرُ خَمْسِينَ آيَةً.