Now, I am apprising you of what befell ‘Uthmān so (correctly) that its hearing may be like its seeing. People criticised him, and I was the only man from among the muhājirūn (immigrants) who asked him to seek to satisfy (the Muslims) most and to offend them the least. As for Ṭalḥah and az-Zubayr, their lightest step about him was hard and their softest voice was strong. ‘Ā’ishah too was in a rage with him. Consequently, a group overpowered him and killed him. Then, people swore allegiance to me, not by force or compulsion, but obediently and out of free will.
You should know that Medina has been vacated by its residents and they have abandoned it. It is boiling like a huge cooking pot and rebellion is fixed on its axis moving with full force. So, hasten towards your amīr (commander) and proceed forward to fight your enemy, if so wills Allāh to Whom belongs Might and Majesty.
 Ibn Maythman writes (in Sharḥ Nahj al-balāghah, vol. 4, p. 338) that when on hearing about the mischief-mongering of Ṭalḥah and az-Zubayr, Amīr al-mu’minīn set off for Baṣrah, he sent this letter to the people of Kūfah through Imām al-Ḥasan and ‘Ammār ibn Yāsir from al-Mā’ al-‘Adhb, while Ibn Abi’l-Ḥadīd has written (in Sharḥ Nahj al-balāghah, vol. 14, pp. 8, 16; aṭ-Ṭabarī, vol. l, p. 3139; and Ibn al-Athīr, vol. 3, p. 223) that when Amīr al-mu’minīn camped at ar-Rabadhah, he sent this letter through Muḥammad ibn Ja‘far ibn Abī Ṭālib and Muḥammad ibn Abī Bakr. In this letter Amīr al-mu’minīn has clearly thrown light on the point that the assassination of ‘Uthmān was the result of the efforts of ‘Ā’ishah, Ṭalḥah and az-Zubayr, and that it was they who took a prominent part in it. In fact, ‘Ā’ishah went beyond her bounds and exposed his shortcomings in public meetings and ordered that he should be killed. Thus, ash-Shaykh Muḥammad ‘Abduh has written:
Once ‘Uthmān was on the pulpit when Umm al-mu’minīn ‘Ā’ishah took out the shoes and the shirt of the Prophet (may Allāh bless him and his descendants) from under her veil and said: “These are the shoes of the Messenger of Allāh and his shirt, not yet decayed, while you have altered his religion and changed his sunnah.” Upon this, hot words followed between them when she said, “Kill this Na‘thal,” symbolising him as a long bearded Jew (of that name). (Nahj al-balāghah, printed in Egypt, vol. 2, p. 3; also see Ansāb al-ashrāf, vol. 5, p. 88; Abu’l-Fidā’, vol. l, p. 172).
People were already displeased with ‘Uthmān, so this event increased their boldness and they surrounded him so that he might mend his ways or abdicate from the caliphate. In these circumstances, there was serious apprehension that if he did not accept either of the two alternatives he would be killed. All this was observed by ‘Ā’ishah, but she paid no heed to it and, leaving him in the siege, decided to leave for Mecca, although on this occasion Marwān ibn al-Ḥakam and ‘Attāb ibn Asīd did say to her, “If you postpone your departure it is possible his life may be saved and this crowd may disperse” whereupon she said that she had decided to go for ḥajj (pilgrimage) and that that could not be changed. Then Marwān recited this couplet by way of a proverb:
Qays set fire to my cities, and when they came into flames he slipped away saving himself clear of it.
Similarly, Ṭalḥah and az-Zubayr were (also) in rage against him and they were ever forward in fanning this fire and intensifying the opposition. From this angle they were, to a great extent, taking part in his assassination and responsible for his blood. Other people also knew them in this perspective and regarded them as his murderers, while their supporters too were not able to offer any explanation (for absolving them). Thus, Ibn Qutaybah writes that when al-Mughirah ibn Shu‘bah met ‘Ā’ishah at Awṭās he asked her:
“O Umm al-mu’minīn, where are you bound for.” She replied, “I am going to Baṣrah.” He inquired for what purpose and she replied, “To avenge ‘Uthmān’s blood.” He said, “But his assassins are with you.” Then he turned to Marwān and enquired where he was going. He replied that he too
was going to Baṣrah. He enquired the purpose and the reply was “to avenge ‘Uthmān’s blood.” Then he said, “‘Uthmān’s assassins are with you. These Ṭalḥah and az-Zubayr have killed him.” (al-Imāmah was’siyasāh, vol. 1, p. 60)
In any case, when, after laying the blame on Amīr al-mu’minīn, this group who had killed ‘Uthmān reached Baṣrah, Amīr al-mu’minīn also rose to quell this mischief and wrote this letter to the people of Kūfah to seek their support. Upon this their combatants and warriors rose in large numbers and enlisted in his army. They faced the enemy with full courage which Amīr al-mu’minīn also acknowledged. Thus, the letter hereafter is in acknowledgement of this very fact.