be carved in stone

be carved in stone

To be made permanent, typically of a plan or idea. We might get brunch next weekend, but nothing is carved in stone yet.
See also: carve, stone
Farlex Dictionary of Idioms.

be carved (or set or written) in stone

be fixed and unchangeable.
The reference here is to the biblical Ten Commandments, written on tablets of stone by God and handed down to Moses on Mount Sinai (Genesis 31:18).
See also: carve, stone
Farlex Partner Idioms Dictionary

be carved/set in ˈstone

(of a decision, plan, etc.) unable to be changed: People should remember that our proposals aren’t carved in stone.
See also: carve, set, stone
Farlex Partner Idioms Dictionary
See also:
  • be carved/set in stone
  • carve
  • set in stone
  • carve (something) in stone
  • carve in stone
  • carved in stone
  • stone me!
  • stone the crows
  • stone the crows!
  • stone cold