Light and life are closely connected. Whether knowledge, purity, or joy is regarded as the dominant idea in the symbol, or whether all are united in it, the profound words of the psalm are true. In God's light we see light. In the lowest region "the seeing eye is from the Lord." "The inspiration of the Almighty giveth understanding." Faculty and medium of vision are both of Him. But hearts in communion with God are illumined, and they who are "in the light" cannot walk in darkness. Practical wisdom is theirs. The light of God, like the star of the Magi, stoops to guide pilgrims' steps. Clear certitude as to sovereign realities is the guerdon of the guests of God. Where other eyes see nothing but mists, they can discern solid land and the gleaming towers of the city across the sea. Nor is that light only the dry light by which we know, but it means purity and joy also; and to "see light" is to possess these too by derivation from the purity and joy of God Himself. He is the "master light of all our seeing." The fountain has become a stream, and taken to itself movement towards men; for the psalmist's glowing picture is more than fulfilled in Jesus Christ, who has said, "I am the Light of the world; he that followeth me shall not walk in darkness, but shall have the light of life."
The closing division is prayer, based both upon the contemplation of God's attributes in vv. 5, 6, and of the wicked in the first part. This distinct reference to both the preceding sections is in favour of the original unity of the psalm. The belief in the immensity of Divine loving-kindness and righteousness inspires the prayer for their long-drawn-out (so "continue" means literally) continuance to the psalmist and his fellows. He will not separate himself from these in his petition, but thinks of them before himself. "Those who know Thee" are those who take refuge under the shadow of the great wing. Their knowledge is intimate, vital; it is acquaintanceship, not mere intellectual apprehension. It is such as to purge the heart and make its possessors upright. Thus we have set forth in that sequence of trust, knowledge, and uprightness stages of growing Godlikeness closely corresponding to the Gospel sequence of faith, love, and holiness. Such souls are _capaces Dei_, fit to receive the manifestations of God's loving-kindness and righteousness; and from such these will never remove. They will stand stable as His firm attributes, and the spurning foot of proud oppressors shall not trample on them, nor violent hands be able to stir them from their steadfast, secure place. The prayer of the psalm goes deeper than any mere deprecation of earthly removal, and is but prosaically understood, if thought to refer to exile or the like. The dwelling-place from which it beseeches that the suppliant may never be removed is his safe refuge beneath the wing, or in the house, of God. Christ answered it when He said, "No man is able to pluck them out of my Father's hand." The one desire of the heart which has tasted the abundance, satisfaction, delights, fulness of life, and clearness of light that attend the presence of God is that nothing may draw it thence.
Prayer wins prophetic certitude. From his serene shelter under the wing, the suppliant looks out on the rout of battled foes, and sees the end which gives the lie to the oracle of transgression and its flatteries. "They are struck down," the same word as in the picture of the pursuing angel of the Lord in Psalm xxxv. Here the agent of their fall is unnamed, but one power only can inflict such irrevocable ruin. God, who is the shelter of the upright in heart, has at last found out the sinners' iniquity, and His hatred of sin stands ready to "smite once, and smite no more."