Where did the phrase "once in prison" in two poems by revolutionary martyrs come from?

He Jingping (1918-1949)1948 wrote this poem in Zhazidong in the summer:

In order to avoid the pain of the next generation,

We want to-

I would like to sit in this prison!

We were born rebels,

We have to turn this upside-down Gankun around!

We are going to knock this unreasonable thing over!

Today, we went to the prison.

What's so rare about going to jail?

In order to avoid the pain of the next generation,

We are willing-willing to sit in this prison!