"Verily, the rising by night (for Tahajjud prayer) is very hard and most potent and good for governing oneself, and most suitable for (understanding) the Word (of Allâh).

Verily, there is for you by day prolonged occupation with ordinary duties.

And remember the Name of your Lord and devote yourself to Him with a complete devotion.

(He Alone is) the Lord of the East and the West; Lâ ilâha illâ Huwa (none has the right to be worshiped but He). So take Him Alone as Wakîl (Disposer of your affairs)."
 
[Al Qur'an; 73:6-9]