Al-Fudayl ‘ibn ‘Iyaad at-Tameemee said: If you are unable to perform Qiyaam al-Layl (pray during the night), and fast during the day, then know that you are deprived, shackled by your sin(s)

Mawaa’ith lil-Imaam al-Fudayl ‘ibn ‘Iyaad. Compiled by Saalih Ahmad ash-Shaamee. al-Maktab al-Islaamee; First Edition 1998/1419 A.H. Reference of quote: Siyar A’laam an-Nubalaa’ (8/435)