Since Tang monk's meat can live forever, why doesn't Li Shimin take a bite himself?

Li Shimin didn't know that eating Tangseng meat could make you live forever. Li Shimin is the real dragon emperor. Judging from the title of emperor, he is the son of the Jade Emperor and the agent for the Jade Emperor to rule all peoples. But like Tang Priest, his memory was sealed after his descent, and he didn't remember the things in heaven. The saying that eating Tang monk meat can live forever is only circulated in the demon world, and the mortal world does not know this secret. When Li Shimin met the Tang Priest, he could not live forever after eating the Tang Priest's meat. After the Tang Priest and his party were released from the armed prison, they could only live forever after eating Tang Priest's meat. Bai, next to Wuzhuangguan, was the first to tell the news. The cause of the incident was that Tang Priest ate a ginseng fruit. Li Shimin knew Tang Priest for thirteen years in Zhenguan. At this time, the Tang Priest has not participated in the pilgrimage group, nor has he eaten ginseng fruit, so his meat has no effect of immortality.