"The Messenger of Allah and Zaid bin Thabit had Sahur, then they went and started to pray Subh." We said to Anas: "How long was there between their finishing and their starting to pray?" He said: "As long as it takes a man to recite fifty Verses." (Using translation from Nasāʾī 2157)
تَسَحَّرَ رَسُولُ اللهِ ﷺ وَزَيْدُ بْنُ ثَابِتٍ ثُمَّ قَامَا فَدَخَلَا فِي صَلَاةِ الصُّبْحِ قُلْنَا لِأَنَسٍ كَمْ كَانَ بَيْنَ فَرَاغِهِمَا وَدُخُولِهِمَا فِي الصَّلَاةِ؟ قَالَ قَدْرُ مَا يَقْرَأُ الْإِنْسَانُ خَمْسِينَ آيَةً