The second sentence is, when eating, don't be full of thoughts. This delusion is like a piece of skin giving birth to a lot of bugs, so it is called dermatophagoides! Dermatophagoides will get sick if they eat raw rice!
The third sentence, I'm afraid my explanation is wrong. Try to understand. In other words, when you eat, all kinds of greed, greedy thoughts and other delusions will burn you like fire. You have to live like this all your life, and all you think about in the future is disaster! So whatever you get is a disaster! It's very similar to what is said in the Tibetan scriptures. Floating sentient beings, acting in action, is nothing more than karma and sin! Here is the taste of greedy rice, disgusting!
The whole paragraph is from "Buddha says Buddhist medical classics"!