There’s this post on Tumblr that details what happened. Anyway, Su Dongpo the writer had his own pretensions and wrote this poem to his monk friend, which looked like this:
稽首天中天，
毫光照大千，
八風吹不動，
端坐紫金蓮
I bow my head humbly below the sky.
Tiny rays of light shine through the depths of my being
Immovable even as the strong winds from eight directions blow,
On a low mound, I am seated on a purple and golden lotus.
I took some creative liberties with the translation.
His monk friend wrote “放屁”, (fàng pì) which means fart in Chinese. When he saw what his friend had written, he was like, “Hey! What the hell?”
His friend was calm and merely replied, “The eight winds can’t move you, but a fart sends you across the lake. Hah.”
Su Dongpo was so embarrassed.
Image from China Daily.