Ezekiel 4:3

Then Ezekiel was to place an iron plate between himself and his model of the city and to lay siege to Jerusalem. This was to be a sign to the people of Israel of what God would do to the real Jerusalem (cf. Deuteronomy 28:52-57). The meaning of the iron plate or pan is also debatable, though it appears to have been a common cooking griddle (Heb. mahabhath). It may have signified the Babylonian army that made escape from the city impossible, [Note: Alexander, "Ezekiel," p. 769; Feinberg, p. 33; Cooper, p. 94.] God’s determined hostility against Jerusalem, [Note: Ibid.; Taylor, p. 76.] the barrier of sin that the Jews had raised between themselves and God, [Note: Dyer, "Ezekiel," p. 1235.] or Ezekiel’s protection as he acted out his drama. [Note: Alexander, "Ezekiel," p. 769.] I favor the view that it represented a barrier that existed between the people and God, whom Ezekiel represented, that their sin had erected and that their prayers could not penetrate (cf. Isaiah 58:2; Lamentations 3:44).

Evidently Ezekiel built this model scene without speaking to his audience or explaining what he was doing, and he probably did it just outside his house (cf. Ezekiel 3:24-25).

"The purpose of God in this prophetic act was hardly limited to letting Ezekiel and his countrymen in on the future. More important was their need to see that God was not about to let the sins of the city He had chosen go unpunished." [Note: Stuart, p. 55.]