SHAFAQNA – It is narrated from Imam Sadeq (AS) who said: A man wrote in his letter to Abu Dhar (RA): O’ Abu Dhar, teach me something new of your knowledge. In reply, Abu Dhar (RA) wrote: There is a lot of knowledge, but if you can, do not do badly to someone whom you love. In another letter that man asked Abu Dhar (RA): Is it t possible to do badly to someone whom you love? Abu Dhar (RA) wrote back: Yes, you love yourself more than anyone else; and if you commit a sin against God, you have done badly (you have been unkind) to yourself .
 Al-Shafi, Page 867.