The Lord lift up his countenance upon thee. ἐπάραι … τὸ πρόσωπον αὐτοῦ ἐπὶ σέ, Septuagint. This clause seems to repeat the last in a somewhat stronger form, as implying more personal and individual attention from the Lord.
His face shines upon all that love him, as the sun shines wherever no clouds intervene; but his face is lifted up to that soul for which he has a more special regard. נָשָׂא פָגִים אֶל seems to mean the same thing as נָשָׂא עֵינַיִם or שִׂיס (Genesis 43:29, ἀναβλέψας … τοῖς ὐφθαλμοῖς αὐτοῦ; Genesis 44:21).
To lift up the eyes or the face upon any one is to look upon that one with peculiar and tender interest. And give thee peace (shalom). This peace, being the perfect fruit in experience of the grace which comes from God, forms the climax and conclusion of the benediction.