3 And now the LORD has brought it about; he has done just as he said he would. All this happened because you people sinned against the LORD and did not obey him.

Read Jeremiah 40:3 Using Other Translations

Now the LORD hath brought it, and done according as he hath said: because ye have sinned against the LORD, and have not obeyed his voice, therefore this thing is come upon you.
The LORD has brought it about, and has done as he said. Because you sinned against the LORD and did not obey his voice, this thing has come upon you.
just as he said he would. For these people have sinned against the LORD and disobeyed him. That is why it happened.