8. light—emblem of prosperity (Isa 58:10; Job 11:17).
health—literally, a long bandage, applied by surgeons to heal a wound (compare Isa 1:6). Hence restoration from all past calamities.
go before thee—Thy conformity to the divine covenant acts as a leader, conducting thee to peace and prosperity.
glory … reward—like the pillar of cloud and fire, the symbol of God's "glory," which went behind Israel, separating them from their Egyptian pursuers (Isa 52:12; Ex 14:19, 20).