1. The vision is of a plumb-line, a line with a plummet at the end of it, such as masons and bricklayers use to run up a wall by, that they may work it straight and true, and by rule. (1.) Israel was a wall, a strong wall, which God himself had reared, as a bulwark, or wall of defence, to his sanctuary, which he set up among them. The Jewish church says of herself (Cant. viii. 10), I am a wall, and my breasts are like towers. This wall was made by a plumb-line, very exact and firm. So happy was its constitution, so well compacted, and every thing so well ordered according to the model; it had long stood fast as a wall of brass. But, (2.) God now stands upon this wall, not to hold it up, but to tread it down, or, rather, to consider what he should do with it. He stands upon it with a plumb-line in his hand, to take measure of it, that it may appear to be a bowing, bulging wall. Recti est index sui et oblique—This plumb-line would discover where it was crooked. Thus God would bring the people of Israel to the trial, would discover their wickedness, and show wherein they erred; and he would likewise bring his judgments upon them according to equity, would set a plumb-line in the midst of them, to mark how far their wall must be pulled down, as David measured the Moabites with a line (2 Sam. viii. 2) to put them to death. And, when God is coming to the ruin of a people, he is said to lay judgment to the line and righteousness to the plummet; for when he punishes it is with exactness. It is now determined: "I will not again pass by them any more; they shall not be spared and reprieved as they have been; their punishment shall not be turned away," ch. i. 3. Note, God's patience, which has long been sinned against, will at length be sinned away; and the time will come when those that have been spared often shall be no longer spared. My spirit shall not always strive. After frequent reprieves, yet a day of execution will come.