cast in stone

cast in stone

Permanently fixed or firmly established; not subject to any amendment or alteration. Often used in the negative. The deal isn't yet cast in stone, but we're confident it will go ahead as hoped.
See also: cast, stone
Farlex Dictionary of Idioms. © 2015 Farlex, Inc, all rights reserved.

cast in stone

Also, etched in stone. Definite, fixed, as in We may choose to stay longer-our plans aren't cast in stone, or When Carl sets an agenda you can safely assume it's etched in stone. Both expressions allude to sculpture, with the first, from the early 1500s, using the verb cast in the sense of pouring and hardening some material into a final form, and the second cutting or corroding a permanent design.
See also: cast, stone
The American Heritage® Dictionary of Idioms by Christine Ammer. Copyright © 2003, 1997 by The Christine Ammer 1992 Trust. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.

in stone, cast/carved/written

Completely set, unchangeable. This phrase is often put in the negative—something is not cast in stone. It alludes to sculpture, where to cast means to pour and harden a material into a final form, and possibly also to the epitaphs engraved on gravestones. The first usage dates from the early 1500s. Most often it appears in such statements as, “Of course we can change it; this proposal is not cast in stone.”
See also: carve, cast, written
The Dictionary of Clichés by Christine Ammer Copyright © 2013 by Christine Ammer
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