An ancient Arabic proverb: He who kisses the bum receives wind as his reward.
From Kitab al-Hayawan by Abu Uthman 'Amr ibn Bahr Al-Jahiz (776 - 868 AD):
"... A book is a receptacle filled with knowledge, a container crammed with good sense, a vessel full of jesting and earnestness. It can be if you wish more eloquent than Sahban Wa'il, or less talkative than Baqil; it will amuse you with anecdotes, inform you on all manner of astonishing marvels, entertain you with jokes or move you with homilies, just as you please ... I know of no companion more prompt to hand, more rewarding, more helpful or less burdensome, and no tree that lives longer, bears more abundantly or yields more delicious fruit that is handier, easier to pick or more perfectly ripened at all times of the year, than a book... It is a bedside companion that does not interrupt when you are busy but welcomes you when you have a mind to it, and does not demand forced politeness or compel you to avoid its company."
(excerpt in The Penguin Anthology of Classical Arabic Literature quoted from Charles Pellat (ed.), The Life and Works of Jahiz (trans. DM Hawke), 1969.