Because of swearing - Rather, because of the curse denounced against sin Jeremiah 11:3. The mourning probably refers to the drought Jeremiah 12:4.
The pleasant places - “Pastures.”
Their course - Their mode of life.
Their force is not right - “Their heroism,” that on which they pride themselves as mighty men, “is not right,” is wrong (see Jeremiah 8:6 note).