30 April, 1526 saw the publication of Huldrych Zwingli’s Über den ungesandten Sendbrief Fabers Zwinglis Antwort. It demonstrated once again, as if it needed further demonstration, that Zwingli and Faber weren’t any longer capable of being BFF’s (though at one point they actually had been).
Sehend, allerliebsten brueder und fründ, wie der allmechtig gott durch sin sorg, die er für uns treyt, das harfürbringt, darumb wir angsthafft sind, wie es one zerrüttung harfürbracht werde. Ich hatt sorg, wie ich allen glöubigen ze verston gäbe, daß die disputation, gen Baden gelegt, uss dero ufsatz, denen doctor Faber wirbt und schafft, angeschlagen wär; dann ich die untrüw, die mit gaaben und valschem underschieben unwarer dingen, nit gern anrueren wolt. So kumpt der gnädig himmelisch vatter und hat Johannsen Fabern die sporn also ggeben, das er hinden und vor ufschlecht und springt, daß imm alles das uss dem sack empfalt, daran man den ufsatz offenlich erkennt. Gott sye gedancket, der unser nimmer vergißt!
And those are just the opening lines. As Schaff notes
The question of the Reformation was repeatedly brought before the Swiss Diet, and not a few liberal voices were heard in favor of abolishing certain crying abuses; but the majority of the cantons, especially the old forest-cantons around the lake of Lucerne, resisted every innovation. Berne was anxious to retain her political supremacy, and vacillated. Zwingli had made many enemies by his opposition to the foreign military service and pensions of his countrymen. Dr. Faber, the general vicar of the diocese of Constance, after a visit to Rome, openly turned against his former friend, and made every effort to unite the interests of the aristocracy with those of the hierarchy. “Now,” he said, “the priests are attacked, the nobles will come next.” At last the Diet resolved to settle the difficulty by a public disputation.
Further on Faber, a very brief note by Walther Köhler titled War Johann Fabri von Leutkirch Dominikaner?
The debates of the 16th century which centered so on the question of the Supper may seem excessive to us- but the theology behind the observation of the Eucharist was the central theological theme of the era. If you’re wrong on the Eucharist, you’re wrong on salvation and its acquirement. And if you’re wrong on that, it doesn’t matter what you’re right on.