سورة At-Taubah ( The Repentance ) - الآية 37

Their postponing of the months is nothing but furtherance in disbelief – the disbelievers are misled by it – they decree it lawful in one year and regard it forbidden in another year, in order to equate to the number of the months which Allah has made sacred, and to make lawful what Allah has forbidden; their evil deeds seem good in their sight; and Allah does not guide the disbelievers.