إنَّ المُحَرَّمَ شَهرٌ کانَ أهْلُ الجاهِلِیَّةِ یُحَرِّمُونَ فِیهِ القِتالَ، فَاسْتُحِلَّت فِیهِ دِماؤُنا، وَهُتِکَتْ فِیهِ حُرْمَتُنا، وَسُبِیَ فِیهِ ذَرارِینا وَنِساؤُنا. Muharram is the month when even people of the Jāhillīyya time declared fighting unlawful, [but never less] in that month they declared shedding our blood lawful, trampled upon our honor and captured our children and women.
Bihar al-Anwar, Vol 44, page 283
Imam Ali ibn Musa al-Rida (peace be upon him)Hadith