Bai Zemin was not very clear about what the World Tree was and what its specific purpose was. At the end of the day, there were many legends and mythologies of all kinds that came and went from mouth to mouth and book to book throughout the history of the human race.
Of course, he also didn't know that what was in front of him was actually a fragment of the World Tree Heart. However, just like a person didn't need to eat a pig to recognize one, he was still able to identify the object in the head of the Mana Eater Tree as something extremely rare and valuable.
The reason? In addition to his practically bestial sense howling in his heart for him to take it quickly, Bai Zemin was definitely not blind. In the midst of the darkness that surrounded him after digging more than five kilometers deep, that beautiful faint green shimmer that exuded a kind of warmth that soothed and calmed the soul was definitely not something normal or low-grade.