That wasn't clear to me :-). But even still: the eruv is a rabbinical interpretation, not something attributed to God.
https://voices.sefaria.org/sheets/144163?lang=bi
(Talmudic interpretation doesn’t stress this story because it shows how much Jews love to argue, or because they can win arguments against God. It stresses the story because it demonstrates that the law has been received (“It is not in heaven”) and thus does not need to appeal to God. This, inter alia, is why nobody asks God for their opinion on eruvim.)