Did Martin Luther ever admit that his approval of Philip's bigamy was wrong? I recently learned that in 1540, Martin Luther secretly approved of the bigamous marriage of Philip of Hesse.  Philip had married for political purposes, and then fell in love with someone else.  Philip appealed to the example of the Old Testament patriarchs, and apparently his wife did not object to his marrying again, so Philip turned to several theologians, including Luther, as Woodbridge and James write:


  Philip sought out Luther, as well as Melanchthon and Martin Bucer, as to the permissibility of a bigamous marriage.  Luther had argued years earlier, regarding Henry VIII and Queen Catherine of Aragon, that bigamy was preferable to divorce. Luther fatefully approved the bigamous marriage, partly out of concern for Philip's troubled conscience and partly out of political expediency.  It was a decision that would cost many lives and nearly destroy Lutheranism itself. (Church History, II, 3.IV.A)


Naturally the secret got out and the resulting controversy seriously weakened Philip and, by extension, Lutheranism.  Luther died six years later, so he would have seen some of the results of his approval.

I'd like to know if Luther repented or otherwise expressed that it was morally wrong for him to have approved of this bigamy.  I distinguish that from a mere admission that the approval was inexpedient or unwise, but if only the latter is available, that would be interesting to see as well.
Luther did not recant.

From: John Alfred Faulkner, "Luther and the Bigamous Marriage of Philip of Hesse, The American Journal of Theology Vol. 17, No. 2 (Apr., 1913), pp. 206-231 (on pp. 228-9) -


  Whatever occasional regret on account of the scandal Luther may have felt, he never wavered as to the essential right of his course with Philip. In June, 1540, in a letter to his electoral prince 
  (first printed in 1872) he gives his own philosophy of the matter, and before I close the reader ought to see the important parts of 
  this statement:
  
  
    ..."    If such a matter as this of Philip's came before 
    me today, I would advise as I have already advised. I am not ashamed of 
    such a counsel, even if it should come before all the world...."