I have heard both of the sentences below in quite similar cases. I wonder if you could let me know how can I distinguish between them and how they differ in meaning? do they mean the same thing?
1) Keep your promise.
2) Stand by your promise.
Or I've heard many times they say:
3) I'll keep my word.
4) I'll stand by my word.
I wonder if you could let me know more about these structures.