Bukhari 4:538 This is an extraordinary hadith, because following the Sunnah of Muhammad (Peace Be Upon Him) , prostitutes can be extremely despised figures among most Muslims, yet it expresses the idea that even someone working in one of the most despised of professions, in showing mercy to an animal, can merit the forgiveness of Allah, and the wise.
http://en.wikiquote.org/wiki/Muhammad

All those who listen to me
shall pass on my words to others
and those to others again;
and may the last ones
understand my words better
than those who listen to me directly