Verily, the number of months with Allah is twelve months (in a year), so was it ordained by Allah on the Day when He created the heavens and the earth; of them four are Sacred, (i.e. the 1st, the 7th, the 11th and the 12th months of the Islamic calendar). That is the right religion, so wrong not yourselves therein, and fight against the Mushrikun (polytheists, pagans, idolaters, disbelievers in the Oneness of Allah) collectively , as they fight against you collectively. But know that Allah is with those who are Al-Muttaqun (the pious - see V:2:2). (At-Taubah 9:36)

'Inna `Iddata Ash-Shuhūri `Inda Allahi Athna `Ashara Shahraan Fi Kitabi Allahi Yawma Khalaqa As-Samawati Wa Al-'Arđa Minha 'Arba`atun Ĥurumun Dhalika Ad-Dinu Al-Qayyimu Fala Tažlimū Fihinna 'Anfusakum Wa Qatilū Al-Mushrikina Kaffatan Kama Yuqatilūnakum Kaffatan Wa A`lamū 'Anna Allaha Ma`a Al-Muttaqina