Here the priestly blessing of Numbers 6:24–26 resonates. It shows how essential this blessing was to Israel. God’s grace was indispensable, as well as undeserved. Without God’s help, the life of man and creation dries up. That is why there is a strong desire for God’s light on everyday existence. Hence the prayer that God’s lovely face should continue to shine upon us. Only in this way life is bearable and a blessing.
The meaning of the Hebrew word "סֶֽלָה" (ESV: Selah) is uncertain. It can be a music indication or a pause sign to give extra attention to the foregoing.
1 May God be gracious to us and bless us and make his face to shine upon us, Selah