I have heard it said, "Every Jew must have at least three children (though more is preferable). Two to replace the parents when they die, and at least one more to make up for those lost in the Shoah."
I thought only my parents said this until I read it in a novel recently. I know that to "be fruitful and multiply" is an important value, but articulated like this specifically - is it a popular notion? If so, amongst whom? What is the origin?