Because. This "because" is misleading; there is no argument, but the statement of a supposed fact. The particle so rendered merely serves to introduce the speech of the Jews (like ὅτι). Shall turn; rather, hath turned.
Judah had so long been undisturbed by any foreign power, that the people fancied the promises of Deuteronomy were being fulfilled, and that they, on their part, had pleased God by their formal obedience.
I will plead with thee. Here, as in some other passages (e.g. Isaiah 66:16; Ezekiel 38:22), the word includes the sense of punishing.