Sayyiduna Anas (may Allah be pleased with him) narrated that Sayyiduna Zaid bin Thabit (may Allah be pleased with him) informed him that they once ate sahur with the Prophet (peace and blessings of Allah be upon him), then stood up for prayer. I asked how much time elapsed between the two. He replied that it was the amount of time it takes to recite fifty or sixty verses.
Hadith Referenceاللؤلؤ والمرجان / كتاب الصيام / 666
Hadith Gradingمحدثین:«صحیح»
Hadith Takhrij«صحیح، أخرجه البخاري في: 9 كتاب مواقيت الصلاة: 27 باب وقت الفجر»