The usual Chinese word for 'friend' is
pengyou 朋友. Both characters occur seperately in the Yi, and they both have their own meanings.
The old form of
peng 朋
shows two strings of money. In the early days the character was used as
a measure word for money, and in this meaning it is still used in 42-2.
This character has more a business-like meaning, namely that of donor
or money lender. Later on this was broadened to 'friends', but still
with a business connotation.
The old form of
you 友 depicts two hands which point in the same direction: a symbol of help, bonding, friendship.
Peng 朋 occurs 9 times in the Yi (2-0, 11-2, 16-4, 24-0, 31-4, 39-5, 40-4, 41-5, 42-2). 11-2 is amusing to mention here. It says here:
朋亡。得尚于中行。Han Boering translates this as "Do not count on comrades. You are being honoured if you keep to the middle". But today
中行 (with
行 in a different pronunciation, I must add) also means 'The People's Bank of China'. If we read
peng 朋
as 'money lender', then the translation becomes: "you lose a money
lender, but will find esteem at the People's Bank of China'.
You 友 only occurs once in the Yi, namely at 41-3, and the context shows we are dealing with real friends here:
三人行。則損一人。一人行。則得其友。"Three men walking. Therefore reduction with one person. One person walking. Therefore he gets a friend."
A threesome,
it is always difficult. Before you know it you have troubles. Only when
you are alone you will find your true friend.