At dawn the Imam glanced over the army of Yazid and saw ‘Umar ibn Sa’d ordering his forces to march towards him. He gathered his followers and addressed them thus: “Allah has, this day, permitted us to be engaged in a Holy War and He shall reward us for our martyrdom. So prepare yourselves to fight against the enemies of Islam with patience and resistance. O sons of the noble and self-respecting persons, be patient! Death is nothing but a bridge which you must cross after facing trials and tribulations so as to reach Heaven and its joys. Which of you do not like to go from this prison (world) to the lofty palaces (Paradise)?
Having heard the Imam’s address, all his companions were overwhelmed and cried out, “O our Master! we are all ready to defend you and your Ahlul-Bayt, and to sacrifice our lives for the cause of Islam.”
Imam Husayn sent out from his camp one after another to fight and sacrifice their lives in the way of the Lord. Lastly, when all his men and children had laid down their lives, Imam Husayn brought his six-month old baby son ‘Ali al-Asghar, and offering him on his own hands, demanded some water for the baby, dying of thirst. The thirst of the baby was quenched by a deadly poisoned arrow from the brute’s forces, which pinned the baby’s neck to the arm of the helpless father. At last when the six-month old baby also was killed, Imam Husayn addressed Allah: “O Lord! Thy Husayn has offered in Thy way whatever Thou hath blessed him with. Bless Thy Husayn, O Lord! with the acceptance of this sacrifice.
Everything Husayn could do till now was through Thy help and by Thy Grace.” Lastly, Imam Husayn came into the field and was killed, the details of which merciless slaughter are heart rending. The forces of Yazid having killed Imam Husayn, cut and severed his head from his body and raised it on a lance. The severed head of the Holy Imam began glorifying Allah from the point of the lance saying, ‘Allahu Akbar’. All glory be to Allah Who is the Greatest!”
After the wholesale, merciless and most brutal slaughter of the Holy Imam with his faithful band, the helpless ladies and children along with the ailing son of Imam Husayn, Imam ‘Ali Zaynul- ‘Abidin, were taken captives.
Reference: The Fourteen Infallibles