Solayman bin Mahran, said:
I went to jaafar bin Mohammad (A.s.) and I found a group of Shia with him. I heard him say:
O Shia! You should beautify us (in the eyes of people) and not disgrace us (with your actions). Speak kindly to people, hold your tongues,and keep it (your tongues) from meddling and saying offensive words.
(Ref: Amaali of Sadouq 327, Amaali of Tousi 2:55)