Albert Barnes Commentary Ezekiel 13:10

"Because, even because they have seduced my people, saying, Peace; and there is no peace; and when one buildeth up a wall, behold, they daub it with untempered [mortar]:" — Ezekiel 13:10 (ASV)

Wall - A partition wall; in Ezekiel 13:12, the word used is the usual word for the outer wall of a house or city. The fall of the partition wall would perhaps involve the fall of the whole house.

Untempered mortar - Or, whited plaster, employed to patch up a wall, so as to give it an appearance (without the reality) of strength and beauty. . In the original there is a play upon a word rendered “folly” in Jeremiah 23:13.