Did Martin Luther Say 'The Greater the Sinner, the Greater the Grace'?

Martin Luther's theology of grace was revolutionary -- the idea that salvation comes through faith alone, not through good works, helped spark the Protestant Reformation. His famous 1521 letter to Philip Melanchthon contained the provocative advice 'sin boldly, but believe more boldly still,' which has been debated by theologians for five centuries. However, the neat formulation 'The greater the sinner, the greater the grace' is not a direct Luther quote but rather a distillation of Pauline theology from Romans 5:20. Luther himself would likely have objected to this simplified version, as he was careful to distinguish between the theological truth that grace covers all sin and any suggestion that one should sin deliberately to receive more grace. The simplification strips away the dialectical tension that was central to his actual theological thinking.