In these verses, Yahweh speaks of the false security that the prophets have given to the people by speaking of peace as if the prophets had built a poorly-constructed wall and covered it over with white paint in order to make it look good. (See: [[rc://en/ta/man/jit/figs-metaphor]])
Yahweh speaks of the prophets deceiving the people and getting them to believe lies as if the prophets had led the people away from the path upon which they should have been walking. (See: [[rc://en/ta/man/jit/figs-metaphor]])
Here "a wall" stands for peace and security that the false prophets told the people that Yahweh was promising to give them. (See: [[rc://en/ta/man/jit/figs-metaphor]])