The engagement.

Ruth and Golda were walking along Hendon High Street.

Ruth says, "My son Irving is getting married. He tells me he is engaged to a wonderful girl, but... he thinks she may have a disease called herpes.

Golda says, "Do you have any idea what this herpes is, and can he catch it?"

Ruth replies, "No, but I am just so thrilled to hear about Irving's engagement - it's time he settled down. As far as the herpes goes...who knows?"

"Well," says Golda, "I have a very good medical dictionary at home. I'll look it up and call you."
So Golda goes home, looks it up, and calls Ruth. "Ruth, I found it. Not to worry. It says herpes is a disease of the gentiles."