Money, coins.
This medieval Chinese term refers to the fact that the traditional Chinese coin (one "cash") has a square hole in the middle.
The term "Brother Square-Hole" (
Kong1-fang1 xiong1) originates with Lu3 Bao1, a
Jin dynasty author, whose "Essay on the God Cash" contains this description:
The body of Cash
bears the Signs of Qian and Kun
:
Internally he is square;
externally he is round.
...He is deified and treasured by all the world.
We call him elder brother, as though kin;
his courtesy name is Square-Hole.
The Song dynasty poet Huang Tingjian has a line describing being out of money:
"Brother Square-Hole writes a letter breaking off relations".
Other Chinese literary allusions