The phrase starting with the words עושה שלום במרומיו ("He who makes peace in his high places") is said in 3 places and always at the end (or very near it):
- Birkat Hamazon
- Kaddish
- Shmoneh Esreh
What is the origin of this phrase and why are these 3 items considered important to share the same phrase? Is there any relationship / commonality of these items that warrants a concluding phrase dealing with the theme of peace?