On cows singing... and the sun standing still (how long is a key discussion), among other miracles from the Bible. Plus, the story of Nakdimon. Also, working off the mishnah, on seclusion - a Jewish woman is not allowed to seclude herself with a non-Jew. Nor should a Jewish man seclude himself with a non-Jew, with all kinds of complicated thinking regarding what happens if men met while traveling, and so on (to the extent of one's sword side, etc.).