The ancients used toilets to teach reading, and there is a word called 浵 .

It's not surprising to use the toilet to read a book, probably what you want to say is the idiom of chiseling the wall and stealing the light.

Chisel into the wall to steal the light. Allusion: In the Western Han Dynasty, there was a very studious man Kuang Heng, but because his family was too poor and had no money to light the lamp, his house was dark at night, and there was no way to study. So what can I do?

One night, when he saw a candle lit in his neighbor's house, he secretly cut a small hole in the wall so that the faint candlelight could shine through the hole in the book, and in this way, he read by the candlelight of the house next door every night until the lights went out. It was in such a poor learning environment that Kuang Heng overcame many difficulties and difficulties, created conditions, learned knowledge, and later became a famous scholar in the Western Han Dynasty.

This means that the external environment and conditions are important factors for people to learn, but not the decisive factor, and the key to a person's achievements lies in their hard work.