Ki Tisa - Sh'vi'i

The mitzvos G-d gave Moshe in the previous aliyah essentially parallel those given in the fifth aliyah of parshas Mishpatim, before Moshe originally ascended Mt. Sinai. They are repeated because Moshe must now re-climb the mountain and take down the Law again. He spent another 40 days on Mt. Sinai without eating or drinking, obtaining another pair of tablets Divinely-inscribed with the Ten Commandments.

When Moshe came down, his face was literally shining from the experience. That can be pretty intimidating for us normal folk, so Moshe had to put on a hoodie. He removed the hoodie when he would speak with G-d and replaced it when he went out to speak to the people.

The word for a ray, as in a ray of light, is the same as the word for a horn. When the Torah says that Moshe's face shone (karan ohr), it was mistranslated as keren, a horn. This led to Michelangelo's statue of Moses with horns and the anti-Semitic propaganda that Jews have horns, which, believe it or not, persists to this day. (For the record, we don't.)