(470) بَابُ التَّسْلِيمِ عَلَى الأَمِيرِ
'Ubaydullah ibn 'Abdullah said, "Mu'awiya went on his first hajjwhen he was the khalifa and 'Uthman ibn Hanif al-Ansari came to him andsaid, 'Peace be upon you, Amir, and the mercy of Allah.' The people ofSyria objected to that and said, 'Who is this hypocrite who shortens thegreeting of the Amir al-Mu'minin!' 'Uthman made his camel kneel and said,'Amir al-Mu'minin! These men object to something which you know betterthan them. By Allah, I used to this greeting for Abu Bakr, 'Umar, and 'Uthman,and none of them objected to it.' Mu'awiya said to those of the peopleof Syria who had spoken, 'Take it easy! It was partly as he stated. Butwhen the civil war engaged the people of Syria, they said, "Do not shortenthe greeting of our khalifa in our presence (i.e. from Amir al-Mu'mininto Amir)." People of Madina, I will treat you as friends even though youuse 'Amir" for a zakat collector.'"
Reference: Al-Adab Al-Mufrad 1024
In-book reference: Book 42, Hadith 61
English translation: Book 42, Hadith 1024