Al-Imām ibn al-Jawzi [may Allāh have mercy on him] said:
“These virtuous days and nights [in the blessed month of Ramadān] are not suitable for the individual to be heedless concerning them, because if the merchant is heedless concerning the season of profit, then when will he make a profit?
Minhāj ul-Qāsideen, 1/343 | Al-Imām ibn al-Jawzi [may Allāh have mercy on him]