We Jews are not only not allowed to conduct business on Shabbes, we are not even supposed to talk about it—
Yosef and Gideon meet in the synagogue one Shabbes morning.
Yosef says, “Not to talk about it on Shabbes, but I’m selling my car.”
Gidon replies, “Not to talk about it on Shabbes, but how much are you asking for it?”
“Not to talk about it on Shabbes, but $13,000.”
“Not to talk about it on Shabbes, but I’ll give you $12,000 for it.”
“Not to talk about in on Shabbes, but let me think about it.”
They meet again in the synagogue Shabbes afternoon.
“Not to talk about it on Shabbes, but did you think about my offer?”
“Not to talk about it on Shabbes, but I already sold it.”
From Oy! The Ultimate Book of Jewish Jokes, by David Minkoff