Yitro

Yitro (Jethro), Moshe's father-in-law, brings Moshe's wife Tzipporah, and their two sons, Gershom and Eliezer, back to Moshe in the wilderness. Yitro observes that Moshe is the sole judge of any disputes. He says that this system cannot work in the long term, and helps Moshe set up a new system of law, by training and appointing judges at various levels to judge simpler cases, thus only the most complicated disputes will actually come before Moshe. He refuses Moshe's offer that he stay with the Jews in their journey through the desert, and returns to his own land.
In the third month after leaving Egypt the Children of Israel come to the Sinai desert and encamp at the foot of Mount Sinai. Moshe ascends the mountain. G-d tells Moshe to tell the people to spend three days preparing themselves, and to set up fences to prevent them going near the mountain. On the third day, G-d reveals Himself in a cloud of smoke and fire, accompanied by the blast of a shofar. G-d gives the Ten Commandments to the people. The people tremble with fear from hearing G-d's speech, and ask Moshe to act as an intermediary, relaying the Divine words to them. The portion ends with instructions prohibiting making idols, and instructions for building the altar.