The narrations indicate that Imam al-Hussayn (peace be upon him) wrote a letter to the people of Kufa in response to their messages that he received. Imam (peace be upon him) asked for ink and paper, and addressing to some of the elders of Kufa about whom he knew that they have still remained steadfast to their commitments wrote in his letter:
“Your letter have been received by me, your messenger came near me and told me that you had taken the oath of allegiance, will never leave me alone in the battlefield, and will never surrender me to the enemy. Now if you are still steadfast to your allegiance - which is the way of reward and salvation - I am with you, my family with your family, and I will be you leader. And if you don't want to do that, you are no longer committed to your promises, have withdrawn your allegiance from yourselves, by my own soul I won't be surprised, because I have seen your behavior with my father, brother and cousin Muslim. Whoever is tricked by your fraud is an amateur, whomever breaks his commitment will suffer its consequences, and Allah will soon make me needless of you. And peace!"
Imam (peace be upon him) closed, sealed and handed over the letter to Qays Ibn Musahhir al-Saydawi, so that he should go to Kufa.
Qays Ibn Musahhir was a leading member of the Shia community in Kufa. He had been sent by the people of Kufa to persuade Imam al-Hussayn (peace be upon him) to accept the invitation to go to Kufa as their Imam.
It was upon his arrival in Mecca that Imam (peace be upon him) began to seriously consider going to Kufa and sent Moslim Ibn ‘Aqeel as his envoy to study the situation there and report to Imam al-Hussayn (peace be upon him). Qays rode to Kufa with Moslim and brought back to the Imam al-Hussayn (peace be upon him) Moslim's message of the sincerity of the people of Kufa.
Qays Ibn Musahhir decided to stay on with the Imam so that he could proudly ride into Kufa with the grandson of the Holy Prophet (Allah’s prayers be upon him and upon his holy Household).
When they reached the fourth stop of the journey, Imam al-Hussayn (peace be upon him) decided to send a letter to the people of Kufa telling them of his departure from Mecca and that he would shortly arrive in Kufa. He gave this letter to Qays and asked him to take it to Kufa.
Qays was proud to be Imam's messenger. Indeed he is known in history as the ambassador of Imam al-Hussayn (peace be upon him). He galloped towards Kufa. When he reached al-Qadisiyah, on the outskirts of Kufa he was astonished to see a large garrison of soldiers guarding the borders of the city. He suspected something was wrong. He hid behind the bushes. He waited until sunset. Carefully, Qays tried to make his way into Kufa. He was spotted by some soldiers. Qays fought them bravely. However, Ibn al-Numayr, the commander of al-Qadisiyah came to the scene with a large number of soldiers. Qays was captured and chained. In the morning he was taken before Ibn Ziyad.
Ibn Ziyad promised Qays to spare his life if he would mount the minbar and curse Imam al-Hussayn. Qays mounted the minbar and in a loud voice said: "O people of Kufa I am the messenger of Imam al-Hussayn Ibn Ali. I declare before you that al-Hussayn, the grandson of our Holy Prophet is the best man alive today."
Saying this Qays looked at Ibn Ziyad defiantly. He then called for the curse of Allah upon Ibn Ziyad and Yazid, and called for Allah's blessings upon Imam Ali and Imam al-Hussayn.
Ibn Ziyad ordered Qays to be taken to the roof of the palace and thrown to the ground. As he mounted the steps, there was a smile on the lips of Qays. As he was being pushed off the roof, Qays cried out: "Peace be upon you O my master al-Hussayn!"
When Imam (peace be upon him) was informed about Qays' being killed, he cried and tears rolled upon his cheeks and said: "O Lord, Assign an exalted position near You for us and our Shi'a, and join us with them under the canopy of your blessings, because You are Omnipotent to do every thing."