Mention of the Festival of Ashura

It is in the Month of Muharram, the beginning of the Arab year, and it is the tenth day of the month. It is the day in which the common people (al-Ammah) and the exoteric of the Shia narrated and alleged that therein lies the killing of our Master al-Husayn (Mighty is His Glory)—High is Allah exalted above what the wrongdoers say, with a great exaltation.

That is because Yazid bin Mu'awiyah (may Allah curse them both) commanded al-Samir bin Marjanah bin Dhi al-Jawshan al-Dabbi (may Allah curse them) after the journey of our Master al-Husayn (Mighty is His Glory) from Medina to Kufa. So he marched against him with the army, and the incident took place on the bank of the Alqami. And [regarding] what occurred there of killing and taking captives, and the transporting of the Head to Yazid, and the manifestation of Occultation (Ghayba) by our Master al-Husayn therein—Majestic is He who does not go absent—and he cast his likeness upon Hanzalah bin Sa'd al-Shaba'i.

His biography was close to the biography of our Master the Christ (Mighty is His Glory) and what he manifested of killing and crucifixion, and the rest of his biography. So the Christians believed regarding him that the killing and crucifixion were true; likewise, the entirety of the common Muslims and the exoteric Shia believed that the killing was true, and they aligned with the Christians in this saying.