Drop down to verse 10, The princes means the leaders. It is a general term. Sometimes it can mean the political leaders - as the king, or all of the ministers that serve under him in exercising the government over the land. It can also mean the spiritual leaders, as well. It can mean the high priest, and all of the priests under him, and the Levites who were serving at the Temple.
That kind of a description gives you an indication that they were doing something pretty bad in the eyes of God. When it said that they were like those who remove a landmark, do you know what he is talking about? If you know anything about the laws regarding land (that appear back in the Pentateuch), land was never supposed to pass from a family. Once it was given to a family, it was to stay in that family. The reason for that, brethren, is because all wealth comes out of the ground.
When people had property - that they could either get minerals from, or that they could farm (or have orchards on, or have cattle grazing on - that ensured that they would have wealth of some type. And it gave stability to the entire financial system; and, besides that, it gave people a sense of being - a sense of being somebody. I am somebody. I own land. I am the equal of my neighbor. And when land, or property, passes from a person, it does a great deal more than just make that person poor.
Well, what he is originally describing here were unscrupulous people who went out in the middle of the night, and they removed the landmark and made their own land bigger by taking away land from their neighbor. The landmarks, at that time, were really nothing more than a stone, or a pile of stones, or a pillar that was stuck up. And so they would go out in the middle of the night and they would move it over twenty feet or so. And now, That land belongs to me! See, that's where the landmark is.
The phrase came to mean anybody who made a gain by doing something deceitful under the cover of secrecy, or darkness. But over time, the phrase began to be an idiom that meant anybody who was playing fast and loose with the law of God.
Instead of having a straight and narrow way that defined the way of God, God is describing, here, the Jews as being someone who blurred the difference between right and wrong, by constantly moving the walls (the sides, the boundaries, the borders) between right and wrong. In other words, they were liberalizing the law of God and making the way broad (and leading to destruction), rather than narrow (and leading to life).
