Zayd bin Thabit said, "We ate the pre-dawn meal with the Prophet ﷺ, and then we rose for the prayer."The narrator said, I asked, "How long was the interval between them?"He replied, "The length of fifty verses."He said, the time it takes to recite fifty verses.
حدثنا هناد حدثنا وكيع عن هشام بنحوه إلا أنه قال قدر قراءة خمسين آية
Muslim also related it from the hadith of Waki through the same chain, see the preceding hadith.There is also a report on this topic from Huzaifa [Nasai, no. 2154].