﴿ إِنَّمَا ٱلنَّسِىٓءُ زِيَادَةٌۭ فِى ٱلْكُفْرِ ۖ يُضَلُّ بِهِ ٱلَّذِينَ كَفَرُوا۟ يُحِلُّونَهُۥ عَامًۭا وَيُحَرِّمُونَهُۥ عَامًۭا لِّيُوَاطِـُٔوا۟ عِدَّةَ مَا حَرَّمَ ٱللَّهُ فَيُحِلُّوا۟ مَا حَرَّمَ ٱللَّهُ ۚ زُيِّنَ لَهُمْ سُوٓءُ أَعْمَٰلِهِمْ ۗ وَٱللَّهُ لَا يَهْدِى ٱلْقَوْمَ ٱلْكَٰفِرِينَ ﴾

“The intercalation [of months] is but one more instance of [their] refusal to acknowledge the truth- [a means] by which those who are bent on denying the truth are led astray. They declare this [intercalation] to be permissible in one year and forbidden in [another] year, in order to conform [outwardly] to the number of months which God has hallowed: and thus they make allowable what God has forbidden. Goodly seems unto them the evil of their own doings, since God does not grace with His guidance people who refuse to acknowledge the truth.”

The Arabs derived two advantages from this method of transposition (nasi’)—one was the diverting of the Hajj season to suit commercial requirements and the other was that if fighting against an enemy had to be started in forbidden months (i.e. Muharram, Rajab, Dhu’l-Qa‘dah and Dhu’l-Hijjah), replacing a haram month by a non-haram month legitimised the opening of hostilities. Abraham’s method had formerly been the backbone of Arab tradition, but since the Arabs’ thinking was dominated by commercial considerations and tribal requirements, the nasi’ method found favour with them and they adopted it in their affairs.