What does Gui Ren's signature to save Li Shimin mean?

Gui Ren saved Li Shimin, that is to say, there are noble people to help those who signed this contract. In times of crisis, someone always moves in time to turn the corner. But you usually don't notice this noble person, or even know him at all, so you can only let nature take its course and don't take it too seriously, otherwise it will be counterproductive.