Abdullah ibn Yusuf At-Tanyisi (right click & "save target as") - He was the student of Imaam Maalik. Imaam Bukhari has narrated from him in his Saheeh. [PDF]
The Prophet (sallallaahu alayhe wa sallam) passed by an Ansari man who was counseling his brother on modesty (he was advising him not to be too much shy or modest).