As retold by Bruce Lowitt

The only milk cow in a small town in Poland died. The people could buy a cow from Moscow for 2,000 rubles, or one from Minsk for 1,000 rubles. Being frugal, they bought the cow from Minsk.

The new cow produced buckets of milk at all times. The townspeople decided to buy a bull. It would mate with the cow and produce more cows like it.

So they bought a bull and put it in the pasture with the cow. But whenever the bull came close to the cow, the cow moved away.

The people were very upset and decided to ask their rabbi what to do. They told the rabbi what was happening, that no matter which way the bull approached the cow, the cow would move away.

The rabbi thought about this for a minute and asked, "Did you buy this cow from Minsk?"

The stunned townspeople said, "Yes. How did you know we got the cow from
Minsk?"

And the rabbi said, "My wife is from Minsk."