WHEN TO STOP EATING H 1256 "We partook in 'sahri' (food before commencement of the fast) during the month of Ramadan with Messenger of Allah, praise and peace be upon him, and then stood up for prayer. He was asked what was the interval of time between the two. He replied, 'The time it takes to recite fifty verses (of the Koran).'" R 1256 Bukhari and Muslim with a chain up to Zaid, the son of Thabit who related that the Messenger of Allah, praise and peace be upon him, said this.
1230- وعن زيدِ بن ثابتٍ رضي الله عنه ، قَالَ : تَسَحَّرْنَا مَعَ رسولِ اللهِ صلى الله عليه وآله وسلم ، ثُمَّ قُمْنَا إِلَى الصَّلاَةِ . قِيلَ : كَمْ كَانَ بينهما ؟ قَالَ : قَدْرُ خَمْسين آيةً . متفقٌ عَلَيْهِ .