Though the Lord be high, yet hath he respect unto the lowly. Notwithstanding all God's glory and greatness, he condescends to look upon the lowly, to consider their needs, and to supply them (comp. Isaiah 57:15).
Hence David feels sure that he will not be overlooked (see Psalms 138:7, Psalms 138:8). But the proud he knoweth afar off. God keeps proud men at a distance, does not draw near to them, much less make his abode with them, but leaves them to themselves until they are ripe for punishment.