For, "He who would love life, And see good days, Let him keep his tongue from evil, And his lips from speaking deceit.
The eyes of the Lord are upon the righteous. This is a reference to the providence which God exercises over his people.  Jesus said, "I am with you always, even unto the end of the world.  Amen"  (Matthew 28:20); and that has the same meaning as the clause here.