The orders from Jehovah are upright, causing the heart to rejoice; the commandment of Jehovah is clean, making the eyes shine.

Ps. 19:7-11.

The orders or particularized rules set forth in the Mosaic law were upright, that is, in full harmony with principles of righteousness and justice. By conducting himself in harmony with the conviction that God’s orders are upright, a person would gain an inward happiness, a joy of heart.

Being pure, clean, without any undesirable trait, the commandment of Jehovah makes the eyes radiant with clearness of vision. It enables a person to avoid moral error and to follow an upright course.