Allah said,

[مِنْهَآ أَرْبَعَةٌ حُرُمٌ]

(of them four are sacred). The Arabs used to consider these months sacred during the time of Jahiliyyah, except for a group of them called Al-Basl, who held eight months of the year to be sacred as way of exaggeration in religion. The Prophet said,

«ثَلَاثَةٌ مُتَوَالِيَاتٌ: ذُو الْقَعْدَةِ وَذُو الْحِجَّةِ وَالْمُحَرَّمُ وَرَجَبُ مُضَرَ الَّذِي بَيْنَ جُمَادَى وَشَعْبَان»

(Three are in succession; Dhul-Qa`dah, Dhul-Hijjah and Muharram, and (the fourth is) Rajab [of (the tribe of) Mudar which comes between Jumada (Ath-Thani)] and Sha`ban). The Prophet said "Rajab of Mudar'' to attest to the custom of Mudar, in saying that Rajab is the month that is between Jumada and Sha`ban, not as the tribe of Rabi`ah thought, that it is between Sha`ban and Shawwal, which is Ramadan in the present calendar. The four Sacred Months were made four, three in succession and one alone, so that the Hajj and `Umrah are performed with ease. Dhul-Qa`dah, the month before the Hajj month, was made sacred because they refrained from fighting during that month. Dhul-Hijjah, the next month, was made sacred because it is the month of Hajj, during which they performed Hajj rituals. Muharram, which comes next, was made sacred so that they are able to go back to their areas in safety [after performing Hajj]. Rajab, in the middle of the lunar year, was made sacred so that those coming from the farthest areas of Arabia are able to perform `Umrah and visit the House and then go back to their areas safely. Allah said next,

[ذلِكَ الدِّينُ الْقَيِّمُ]

(That is the right religion), that is the Straight Law, requiring implementing Allah's order concerning the months that He made sacred and their true count as it was originally written by Allah. Allah said,

[فَلاَ تَظْلِمُواْ فِيهِنَّ أَنفُسَكُمْ]

(so wrong not yourselves therein) during these Sacred Months, for sin in them is worse than sin in other months. Likewise, sins in the Sacred City are written multiplied,

[وَمَن يُرِدْ فِيهِ بِإِلْحَادٍ بِظُلْمٍ نُّذِقْهُ مِنْ عَذَابٍ أَلِيمٍ]

(...and whoever inclines to evil actions therein (in Makkah) or to do wrong, him We shall cause to taste from a painful torment) [22:25]. Similarly, sin in general is worse during the Sacred Months `Ali bin Abi Talhah narrated that Ibn `Abbas said, Allah's statement,

[إِنَّ عِدَّةَ الشُّهُورِ عِندَ اللَّهِ]

(Verily, the number of months with Allah...), is connected to

[فَلاَ تَظْلِمُواْ فِيهِنَّ أَنفُسَكُمْ]

(so wrong not yourselves therein), "In all (twelve) months. Allah then chose four out of these months and made them sacred, emphasizing their sanctity, making sinning in them greater, in addition to, multiplying rewards of righteous deeds during them.'' Qatadah said about Allah's statement,

[فَلاَ تَظْلِمُواْ فِيهِنَّ أَنفُسَكُمْ]

(so wrong not yourselves therein), "Injustice during the Sacred Months is worse and graver than injustice in other months. Verily, injustice is always wrong, but Allah makes things graver than others as He will.'' He also said, "Allah has chosen some of His creation above others. He chose Messengers from angels and from men. He also chose His Speech above all speech, the Masajid above other areas of the earth, Ramadan and the Sacred Months above all months, Friday above the other days and Laylatul-Qadr (The Night of Decree) above all nights. Therefore, sanctify what Allah has sanctified, for doing so is the practice of people of understanding and comprehension.''