What does it mean to have ink in your stomach?

[Explanation] There is no ink in my stomach. A man without culture.

[Source] On the volume of Hu Tianlu, a hundred laymen in Huaiyin, Qing Dynasty: "A well-off family is loved by parents because of their only son. After studying for ten years, there is no ink on my chest. "

Although he talks a lot every day, he is actually a good man.

Source song? Shi Puqi's "Five Lights Meeting Yuan": "The teacher praised himself:' The peach spoon is not a villager, and there is nothing in his chest. He once drove emptiness out of his bones and won the Jianghu with evil voice. "

Usage subject-predicate type, often used as predicate and attribute.

So there is ink in my stomach, so I should know and be knowledgeable. ...