For; he now gives a reason of this great difference between the righteous and the ungodly, expressed in the foregoing verses. The Lord knoweth; either,
1. Properly and speculatively; he searcheth and knoweth all their hearts and ways or actions; and therefore will preserve, prosper, and bless them; which may be gathered out of the following and opposite clause of this verse, and out of Psalms 1:1,2. Or,
2. Practically and affectionately, as words of knowledge in Scripture do frequently imply affection, as Exodus 1:8 Psalms 31:7, Psalms 101:4 Hosea 8:4 Amos 3:2. He approveth, loveth, and delighteth in them, and in the course of their lives, and therefore will recompense them; or, he careth for and directeth their actions to a blessed issue. The way of the ungodly shall perish; all their wicked designs and courses shall come to nothing, and they shall perish with them.