Musannaf Ibn Abi Shayba 22:174

Muhammad ibn Bishr narrated to us, he said: Mis'ar narrated to us, from 'Adi ibn Thabit, from Abu Hazim, from Abu Hurayrah, he said: "Whoever recites one hundred verses in a night will not be written among the heedless. And whoever recites two hundred will be written among the devout."