Martin Luther on Psalms 125:4

Verſe 4. Do well O Lord unto them that be good and true of heart. The Prophet ſaith not here: Do well Lord to the perfect, and ſuch as offend in nothing: but, to the good and true of Heart. The good and true of Heart, are they which are of a ſingle, ſincere and upright Heart. For theſe are they which are moſt accepted of God, altho they alſo through infirmity do ſometimes offend. Now where he prayeth that God will do well to the good and godly, he meaneth alſo and ſecretly complaineth that the godly are in miſery and affliction, and that the ungodly do abound with all worldly felicity: As we ſee at this day the Enemies of the Goſpel to enjoy great Riches and Dignities, whereby they vex and oppreſs the godly. This is a great offence and ſtumbling-block to the godly, and therefore the Church hath need of this Prayer, That God would do well unto the godly, which truſt in him, and ſeek his Glory with their whole Heart, that they by ſtumbling at this offence do not fall away to impiety. This Prayer containeth in it a Prophecy with a promiſe, that like as he prayeth for the Bleſſing, Welfare and Proſperity of the juſt, ſo at the length it ſhall alſo come to paſs.