Li Shiji
As the siege continued, on an occasion, when Emperor Taizong heard the sounds of chickens and pigs coming out of the city, he opined to Li Shiji that it must be that the Goguryeo defenders were preparing an assault and were slaughtering animals beforehand to feast on them. Li Shiji therefore prepared for a night assault, which came that very night. Emperor Taizong himself led soldiers to repel the assault, and the Goguryeo forces withdrew within the city again.