Who can help explain the meaning of this obscure joke?

Guo Ke is divided into three parts, the upper left bit represents the height of the upper half; Guo Zuo's son represents Li's lower body; Guo's right represents Chen.

Spring is divided into three parts: man and the sun.

Hai: Homophony is a child.

It means: Gao, Li and Chen, children born in three days.