This request is part of the well-known Mosaic benediction for the children of Israel (Numbers 6:24-27). The first occurrence in verb form of the word "shine" is in this verse, although in the noun form, translated as "light," it appears in the third verse of the Bible when God said, "Let there be light" (Genesis 1:3).
True light comes only from God, since "God is light" (1 John 1:5). As the world depends on the sunshine for its physical life, so we continually must receive the Son's shining in our hearts to sustain our spiritual life.
It is noteworthy that the prayer of our text occurs seven other times in the Scriptures. These are as follows:
"Make thy face to shine upon thy servant: save me for thy mercies' sake" (Psalm 31:16); "God be merciful unto us, and bless us; and cause his face to shine upon us; Selah" (Psalm 67:1); "Turn us again, O LORD God of hosts, cause thy face to shine; and we shall be saved" (Psalm 80:19; also vv. 3, 7); "Make thy face to shine upon thy servant; and teach me thy statutes" (Psalm 119:135); "O our God, hear the prayer of thy servant, and his supplications, and cause thy face to shine upon thy sanctuary that is desolate, for the Lord's sake" (Daniel 9:17).
Since God, in His omnipotence, dwells "in the light which no man can approach unto" (1 Timothy 6:16), He shines on us for salvation, spiritual illumination, and daily guidance only through His Son, the Word made flesh, for "in him was life; and the life was the light of men" (John 1:4). "For God, who commanded the light to shine out of darkness, hath shined in our hearts, to give the light of the knowledge of the glory of God in the face of Jesus Christ" (2 Corinthians 4:6). HMM