Quran 9, Al-Tawba (Repentance) ⓘ

9:37Postponement (of a sacred month) is only an excess of disbelief whereby those who disbelieve are misled; they allow it one year and forbid it (another) year, that they may make up the number of the months which Allah hath hallowed, so that they allow that which Allah hath forbidden. The evil of their deeds is made fairseeming unto them. Allah guideth not the disbelieving folk.

إِنَّمَا النَّسِيءُ زِيَادَةٌ فِي الْكُفْرِ يُضَلُّ بِهِ الَّذِينَ كَفَرُوا يُحِلُّونَهُ عَامًا وَيُحَرِّمُونَهُ عَامًا لِيُوَاطِئُوا عِدَّةَ مَا حَرَّمَ اللَّهُ فَيُحِلُّوا مَا حَرَّمَ اللَّهُ زُيِّنَ لَهُمْ سُوءُ أَعْمَالِهِمْ وَاللَّهُ لَا يَهْدِي الْقَوْمَ الْكَافِرِينَ