In a club, two mediocre players were playing with each other when White exclaimed: "If you move like this, you'll mated." With these words, the president of the club, a famous master, stepped up to the chess board and said: White couldn't possibly Mate. White did not allow himself to be disturbed, however, and moved and mated Black on the second move; and the Mr. President could say nothing more than "Oh I see!"

from Dawson & Hunsdorfer, 1915:
"The actual origin of the en passant analytic is not certain. Way back in 1944, a year before the publication of the Indian problem, old Portius, the genial editor of the Leipzig Illustrated, published No. 53A [this problem] in connection with one of his chess tales. It is simply a trick problem, quite free of any thought of analysis, but we quote it for its historical significant. It set solvers' brains in action, and suggested the possibility of an analytic en passant key. [...] No. 53 [P0001360, 1858] fourteen years after No. 53A, is analytically sound, but unfortunately unidentified." [Author now known to be Max Lange.]
So this is a joke rather than cooked.
Henrik Juel: From the story we know that White can mate in two
this is possible only if last move was f7-f5
then C+ by Popeye 4.61 (2017-09-09)
A.Buchanan: These days this would be regarded as a constrained problem, rather than a joke. wLg4 serves no purpose, as far as I can see. (2020-02-10)
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