A Commentary, Critical, Practical, and Explanatory on the Old and New Testaments, by Robert Jamieson, A.R. Fausset and David Brown  at sacred-texts.com
psa 67:1A prayer that, by God's blessing on His people, His salvation and praise may be extended over the earth. (Psa 67:1-7)
cause his face to shine--show us favor (Num 6:24-25; Psa 31:16).
psa 67:2thy way--of gracious dealing (Isa 55:8), as explained by--
saving health--or literally, "salvation."
psa 67:3Thanks will be rendered for the blessings of His wise and holy government (compare Isa 2:3-4; Isa 11:4).
psa 67:6The blessings of a fruitful harvest are mentioned as types of greater and spiritual blessings, under which all nations shall fear and love God.