Of course, I had to ask. It was Farsi. On this site I've just linked to, I read
Farsi, also known as Persian Language, is the most widely spoken member of the Iranian branch of the Indo-Iranian languages, a subfamily of the Indo-European Languages.
What an interesting place my city is, where I can hear such a variety of languages!
One of the women obliged me by counting to ten in Farsi, which I thought was very kind of her. Here's a link to a list of those numbers.