Food in the Bible generally relates to the desire for good, and drink generally relates to ideas of what is true. It makes sense then, that being hungry represents a lack of good intentions and a desire for them, while thirsting or being thirsty represents a lack of knowledge and a desire to learn what is true about life, the Lord, and what we are called to do and be.

(References: Apocalypse Explained 480; Apocalypse Revealed 381, 889, 956; Arcana Coelestia 4017, 8568)