jūn zǐ zhī jiāo dàn rú shuǐ
a gentleman's friendship, insipid as water (idiom, from Zhuangzi 莊子|庄子[Zhuang1 zi3])
君
jūn
monarch
子
zǐ
son
之
zhī
(possessive particle, literary equivalent of 的[de5])
交
jiāo
to hand over; to deliver; to pay (money); to turn over
淡
dàn
insipid
如
rú
as
水
shuǐ
water