Anas bin Malik said, "The Prophet ﷺ and Zaid bin Thabit took the 'Suhur' together and after finishing the meal, the Prophet ﷺ stood up and prayed (Fajr prayer)." I asked Anas, "How long was the interval between finishing their 'Suhur' and starting the prayer?" He replied, "The interval between the two was just sufficient to recite fifty 'Ayat." (Verses of the Qur'an). (Using translation from Bukhārī 576)
أَنَّ رَسُولَ اللهِ ﷺ وَزَيْدَ بْنَ ثَابِتٍ تَسَحَّرَا فَلَمَّا فَرَغَا مِنْ سُحُورِهِمَا قَامَ رَسُولُ اللهِ ﷺ إِلَى الصَّلَاةِ فَصَلَّى قُلْتُ لِأَنَسٍ كَمْ كَانَ بَيْنَ فَرَاغِهِمَا مِنْ سَحُورِهِمَا وَدُخُولِهِمَا فِي الصَّلَاةِ؟ فَقَالَ قَدْرُ مَا يَقْرَأُ الرَّجُلُ خَمْسِينَ آيَةً