Damn, that's crazy. I've never heard of this. Got any other cool, obscure "scripture?"
Edit: after looking it up, I think the part right after is just as interesting:
The Gemara comments: Come and see the difference between the sinners of Israel and the prophets of the nations of the world. As Balaam, who was a prophet, wished Israel harm, whereas Jesus the Nazarene, who was a Jewish sinner, sought their well-being.