This refers to Matthew 19:29:
Christ does not mean that leaving parents, wife, and siblings is a work that must be done because it merits the forgiveness of sins and eternal life. Indeed, such leaving is cursed. Anyone who leaves parents or wife to merit the forgiveness of sins or eternal life by this work dishonors Christ.
There are two kinds of leaving. One happens without a call, without God’s command, which Christ does not approve (Matthew 15:9). The works we choose are useless services. When Christ speaks about leaving wife and children, it becomes clear that He does not approve this kind of leaving. We know that God’s commandment forbids leaving wife and children. God’s command to leave is different, that is, when power or tyranny pushes us either to leave or to deny the Gospel. Here we are commanded to bear injury and should rather allow not only wealth, wife, and children, but life to be taken from us. Christ approves of this kind of leaving, and so He adds for the Gospel’s “sake.” He does so to illustrate that He is speaking not of those who injure wife and children, but who bear injury because of the confession of the Gospel.
(Apology Article XXVII, par. 40–41 — Concordia p. 243-244)
Doesn’t that call to mind the line from the older, TLH translation of A Mighty Fortress?
Also this (especially for Mary’s consideration, given her interest in past comments):
The division, control, and possession of property are civil ordinances, approved by God’s Word in the commandment “You shall not steal” (Exodus 20:15).
(Apology XXVII, par. 46, same page)
Notice the way this translation is worded here to relate these things to the seventh commandment, especially the word “approved.” Previously I’ve written something like “implied by.”