From Sahih Bukhari (Hadith 575):
Narrated Anas:Zaid bin Thabit said, "We took the "Suhur" (the meal taken before dawn while fasting is observed) with the Prophet (ﷺ) and then stood up for the (morning) prayer." I asked him how long the interval between the two (Suhur and prayer) was. He replied, 'The interval between the two was just sufficient to recite fifty to sixty 'Ayat
Reference: Bukhari 575