Qatādah رضي الله عنه said: “Know that sinning in the sacred months (Dhul-Qa’dah, Dhū al-Ḥijjah, Muḥarram and Rajab) is worse than sinning in other than them even though sinning in all circumstances is something not to be taken lightly (grave), except Allāh magnifies from the affairs that which is pleasing to him.”
● [تفسير ابن كثير ١٤٨/٤، تفسير ابن رجب ٥١٦/١]