Luther advised him against a second marriage.
From the von Ludwig collection at Halle in Schütze, Vol. III, p. 74; in Strobel-Ranner, p. 270 and in De Wette, Vol. V, p. 125 f. German in Walch, Vol. XXI, 1460.
Grace and peace in Christ! My dear Bernard, I will not resist your will if you want to try a shipwreck in marriage for the second time, but there are very many reasons with me, of which it seems to me that they must rightly move you that especially you do not marry for the second time. You know your weakness; then, after this second marriage, you will not be so popular with the people, because of the exceedingly evil people who are very ill-disposed against us in this region. 2) And those who are godly will not marry again. And those who are godly already have enough burdens to carry, so that it is not necessary for them to be burdened by your and similar things. But that moves me, that there is danger that you might find one like the one you lost, and I know your well-known leniency in the government of the household, which is exceedingly burdensome at this time, so that if I were a younger man, I would nevertheless, since I have experienced the wickedness of the world, if a queen were also offered to me after my Käthe, rather die than become a husband anew. Therefore, if you want to hear me, you will refrain from it, so that you do not burden yourself and us further. Farewell in Christ. The last of August 1538.
No. 2460.