Everything about "pox leber" as a minced oath, and an earlier source.

[Battler]

Not sure if it is of any use whatsoever, but I remembered "Samer pox/box/botz" was common in the examples I found previously.
I have no idea what any of these mean.. (translation tools do not have a scooby doo) so hopefully I'm not posting anything offensive... 

"kein wunder wers, sammer botz lung,
das mir vor leid mein herz zersprung."

"samer pox haut!"
"samer pox leichnam!"
"samer pox trost!"

I wonder if this is a German borrowing from some Slavic language, because in Slovenian, we often say "Sam Bog verb in infinitive", eg. "Sam Bog jim pomagej" - "[May] God himself help them". Bog means God. I can see "Sam Bog" turning into "samer pox" in German, with the help of some folk etymology which people like doing on phrases they don't quite understand.