The ninth of Muharram is called Tasua⁽[1]⁾. Imam al-Sadiq is reported to have said, “On the ninth of Muharram, Imam al-Hussein, along with his companions, was besieged in Karbala’ when the Syrian horsemen surrounded him leaving for him but a narrow area. Son of Marjanah (i.e. Ubaydullah ibn Ziyad) and Umar ibn Saʿd were delighted due to the great numbers of the horsemen who participated in that encounter against Imam al-Hussein. Thus, the enemy became sure that no supporter would join the army of Imam al-Hussein and the people of Iraq, in particular, would not back him.” Imam al-Sadiq then added, “May I sacrifice my father for the weak and the stranger (i.e. Imam al-Hussein).”

يوم التّاسوعاء. عن الصّادق (عليه السلام) قال: تاسُوعا يوم حُوصر فيه الحسين (عليه السلام) وأصحابه بكربلاء واجتمع عليه خيل أهل الشّام وأناخوا عليه وفرح ابن مرجانة وعمر بن سعد بتوافر الخيل وكثرتها واستضعفوا فيهِ الحسين (عليه السلام) وأصحابه وأيقَنوا انّه لا يأتي الحسين (عليه السلام) ناصر ولا يمدّه أهل العراق ثمّ قال بأبي المستضعف الغريب