Zaid bin Thabit (May Allah be pleased with him) reported:
We took Suhur (predawn meal) with the Messenger of Allah ﷺ 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].

وعن زيد بن ثابت رضي الله عنه قال: تسحرنا مع رسول الله ﷺ ثم قمنا إلى الصلاة قيل كم كان بينهما؟ قال: خمسون آية ((متفق عليه))