Some people came to Ali and complained about Uthman's tax collectors. Ubayy said to me, "Take this letter to Uthman and tell him that the people have complained about his collectors. This is the directive of the Messenger of Allah ﷺ regarding the alms. Order them to follow it."I went to Uthman and conveyed this to him.The narrator said, "If he were going to mention Uthman with anything," meaning anything negative, "he would have done so on that day."
حدثنا عبد الرزاق أنبأنا ابن عيينة عن محمد بن سوقة عن منذر الثوري
جاء إلى علي رضي الله عنه ناس من الناس فشكوا سعاة عثمان قال فقال لي أبي اذهب بهذا الكتاب إلى عثمان فقل له إن الناس قد شكوا سعاتك وهذا أمر رسول الله ﷺ في الصدقة فمرهم فليأخذوا به قال فأتيت عثمان فذكرت ذلك له قال فلو كان ذاكرا عثمان بشيء لذكره يومئذ يعني بسوء
No references are available.
Its chain of transmission is sahih, and in Dhakhair Mawarith 5411 it is mentioned that Bukhari narrated it.