Mishkat al-Masabih

‘ Amr b. Shu'aib, on his father’s authority, told that his grandfather reported God’s messenger as saying, “God likes the mark of His favour to be seen on his servant.” (People whom God has prospered should wear clothes suitable for their station, for the poor may recognise them as people able to give charity. The learned should not conceal their learning, so that others may benefit from it) Tirmidhi transmitted it.