Holy months in Quran

السلام عليكم ورحمة الله وبركاتة

بِسْمِ ٱللَّٰهِ ٱلرَّحْمَٰنِٱلرَّحِيمِ

Indeed, the number of months with Allāh is twelve [lunar] months in the register of Allāh [from] the day He created the heavens and the earth; of these, four [Rajab, Dhul-Qa'dah,  Dhul-Hijjah and Muharram] are sacred. [Al Quran, 9:36]

They ask you about the sacred months [Rajab, Dhul-Qa'dah,  Dhul-Hijjah and Muharram] - about fighting therein. Say, "Fighting therein is great [sin]...    "  [Al Quran, 2:217]

الحمدلله