For thou art my lamp, O LORD: and the LORD will lighten my darkness.
For thou art my lamp, O Lord. The light of a lamp was an image in common use among the Hebrews for prosperity; while its extinction betokened calamity (Esther 8:16; Job 18:5-6; Job 21:17; Job 29:3; Psalms 97:11; Psalms 132:17; Proverbs 24:20). But х neeyriy (H5216)] the word here denoting a lamp is always applied metaphorically, as expressive of offspring (1 Kings 11:36; 1 Kings 15:4; 2 Kings 8:19; 2 Chronicles 21:7). The meaning then, is, the Lord had not only raised David from a state of obscurity to honour, of trouble to safety, of persecution to freedom and comfort, of inferiority to rank and glory, but conferred upon him, in addition to these personal benefits, the blessing and the dignity of a long-continued royal line.
And the Lord will lighten my darkness - i:e., whatever adversity may for a time befall my house, the Lord will appoint eventual prosperity. My family has been sadly diminished by the excision of several promising branches; but though my prospects have been greatly beclouded, 'the Lord will yet illumine my darkness:' others will, through the blessing of His kind providence, be raised to preserve my roof-tree flourishing in the land; and especially in the appearance of my last and greatest descendant, He will brighten every season of darkness and distress by the light of His salvation.