Thou shalt keep them, O LORD, thou shalt preserve them from this generation for ever.
Thou shalt keep them, O Lord - namely, thy people in safety from their persecutors. From this generation. The corruption was so universal (Psalms 12:1) that the ungodly represent the spirit of the age "from" which the Lord would "preserve" His own chosen few. Compare Galatians 1:4; 1 John 5:19.