Application to Israel: Yahweh understands the nature of Israel’s vacillation. Israel observes the wonders and miracles but misattributes them to idols rather than to the true God. Such idols provide the illusion of power but do not require personal spiritual sacrifice.
Application to Nephi’s audience: Like Israel, Laman and Lemuel have witnessed miracles but attributed them to some other source—perhaps not to idols but to the forces of nature or happenstance. The result is still to effectively deny them.
Variant: The Book of Mormon has an added phrase (in bold): “before it came to pass I showed them thee; and I showed them for fear lest thou shouldst say.… ” There is no textual support in extant manuscripts for this change, but it amplifies the meaning of “lest.” The addition simply makes the English easier to read. Nevertheless, because it improves the English reading (as opposed to the original Hebrew) we can be certain that this is a change that Joseph Smith made rather than one that was on the brass plates.