الكافي- ط الاسلامية, volume 4, page 519

3. Ali ibn Ibrahim has narrated from his father from Ibn Abi ‘Umayr from ‘Umar ibn ‘Udhaynah from Zurarah who has said the following: “Abu Ja’far (a.s.), has said, ‘The Holy Prophet, O Allah, grant compensation to Muhammad and his family worthy of their services to Your cause, performed al-Hajj and stayed in Mina for three days praying two Rak‘ats in each salat (prayer). Abu Bakr also did the same way. Then ‘Umar did in the same way. Thereafter, ‘Uthman did the same way for six years. He then performed four Rak‘at in full. He performed al-Zuhr four Rak‘ats, then he pretended to be ill so he can establish his setup of innovation. He told the person calling Adhan, “Go to Ali and tell him to lead al-‘Asr salat (prayer) for the people.” He went to Ali (a.s.), and said, “’Amir al-Mu’minin, ‘Uthman commands you to lead salat (prayer) with people.” He (the Imam) said, “I will only perform two Rak‘ats just as the Messenger of Allah, O Allah, grant compensation to Muhammad and his family worthy of their services to Your cause, had done.” The person calling Adhan went back and informed ‘Uthman about it. He, ‘Uthman, said, “Go to him and tell him, ‘This is not up to you to decide. Go and lead salat (prayer) with people as you are commanded.’” Ali (a.s.), said, “No by Allah, I will not do so.” ‘Uthman then went and led salat (prayer) with people; four Rak‘ats. During the rule of Mu‘awiyah, when people had gathered around him and ’Amir al-Mu’minin, Ali (a.s.), was martyred, Mu‘awiyah performed al-Hajj. In Mina’ he led al-Zuhr salat (prayer) with people in two Rak‘ats, and finished with Salam. The Amawides looked to each other, so also did Thaqif people as well as Shi`a of ‘Uthman. They then said, “He struck a blow to your companion (‘Uthman), opposed him and made his enemies to ridicule him.” They stood up and went to meet Mu‘awiyah. They said, “Do you know that you, by not increasing, have struck a blow to our companion, ‘Uthman, made his enemies to ridicule him, deviated from his tradition and deeds.” He replied, “Fie upon you, do you not know that the Messenger of Allah, O Allah, grant compensation to Muhammad and his family worthy of their services to Your cause, performed salat (prayer) in this place, two Rak‘ats (in short form) as well as abu Bakr and ‘Umar and also your companion for six years? Now you command me to give up the tradition of the Messenger of Allah, O Allah, grant compensation to Muhammad and his family worthy of their services to Your cause, what abu Bakr, ‘Umar and ‘Uthman had done before he (‘Uthman) invented (the innovation)” They said, “No by Allah, we will not agree with you until you do that.” He then said, “I ask you to pardon me and I accept your intercession on his behalf. I return to the tradition of your companion.” He performed al-‘Asr salat (prayer) in four Rak‘ats. From that time on, the Khalifah and rulers continued performing salat (prayer) in Mina in complete form to this day.’”

Translation: Muhammad Sarwar·Thaqalayn link·The Arabic above is the original.