For thou wilt light my candle - Margin, lamp. The word lamp best expresses the idea. In the Scriptures light is an image of prosperity, success, happiness, holiness, as darkness is the image of the opposite. See the notes at Job 29:2-3; compare also Job 18:6; Job 21:17; Proverbs 20:27; Proverbs 24:20; Psalms 119:105; Psalms 132:17; Isaiah 62:1. The meaning here is, that the psalmist felt assured that God would give him prosperity, as if his lamp were kept constantly burning in his dwelling.
The Lord my God will enlighten my darkness - Will shed light on my path, which would otherwise be dark: will impart light to my understanding; will put peace and joy in my heart; will crown me with his favor. Compare the note at Psalms 4:6.