Although Master Xuanzang is a death row prisoner confined in this death prison, if someone else were to break in and kill him, all of us prison guards would be held responsible.
Therefore, upon hearing Jiang Liu's words that someone would forcefully break in tonight to kill him, this prison guard took it very seriously.
After finding an excuse, he turned around and left the death prison to look for his comrades and mobilize troops to defend.
If someone really did break in, not only could he protect himself, but he could also help his comrades earn a great military merit.
Of course, even if it was a false alarm and no one broke in, it wasn't much of a loss.
It would just mean that his comrades made a trip for nothing.
Moreover, this prison guard had a lot of trust in Master Xuanzang's character.
After finding his comrade, the prison guard explained the situation. The brother, a Chiliarch, also evidently trusted Master Xuanzang's character.