It is important that a lawyer should leave no stone unturned even on minor points and harp on the same subject to achieve a break through in an impasse.
Not to harp on the same string, I still insist that those who drink should never drive.
Monotony develops when you harp on the same string.
He keeps harping on about declining standards in education.
The opposition party is still harping on the scandal.
They could hear the elegant, flowing sound of a harp coming from somewhere.