بِسْمِ اللهِ الرَّحْمنِ الرَّحِيمِ
1230. Zaid bin Thabit (May Allah be pleased with him) reported: We took Suhur (predawn meal) with the Messenger of Allah (PBUH) and then we stood up for (Fajr) Salat (prayer). It was asked: "How long was the gap between the two?'' He replied: "The time required for the recitation of fifty Ayat.''
[Al-Bukhari and Muslim]