What's the next sentence when the mouse enters the lantern?

After the mouse got into the lantern, his next sentence was to eat candles (porridge). As for the two-part allegorical saying that the mouse entered the lantern, the second part is "eat candles (eat porridge)", which means that the mouse entered the lantern and was trapped inside, so it could only eat lamp oil. This is a vivid metaphor to describe the situation of being trapped.