Since parsha Yisro Moshe rabenu has been up on Mount Sinai receiving the Torah for the Jews. This parsha, Ki-Tisa, concludes Moshe's time on the mountain with some more commandments connected with the Mishkan, then tells what happens when Moshe comes down the mountain.
In the first aliyah G-d commands Moshe to count the Jewish people by collecting an atonement offering of half a shekel for each person. The Torah says, "so there will be no plague among them". Rashi explains that by counting the half shekels instead of the Jews, the Jews won't be harmed by the evil eye.
G-d then commands Moshe to make a wash stand of copper for the sanctuary for the Kohanim to wash their hands and feet before their service.
G-d gives Moshe instructions for making the anointing oil with fine spices, to be used for anointing certain items of the sanctuary as well as Aharon and his sons. The formula of the oil is never to be duplicated or used in an unauthorized manner. Similarly a formula is given for incense to be used in the sanctuary, and its unauthorized duplication is also prohibited.
G-d appoints Betzalel the son of Uri to have wisdom, understanding, and knowledge and to be the craftsman of the sanctuary and its contents. G-d appoints Oholiav as his assistant.
Finally, the aliyah ends with G-d telling the Jewish people to keep the Sabbath. Here it says that the Sabbath is an "Os" (sign) between Him and the Jewish people, making us holy.
The second aliyah: Since the ten commandments were given in Parshat Yisro, G-d has been dictating the Torah to Moshe up on mount Sinai and made for him a miraculous set of luchos (tablets). When Moshe went up to the mountain to receive all this, he told the people to expect him back in forty days. But the people erred in their calculation by a few hours and, with the help of the evil inclination and the bad influence of the mixed multitude that were with them, they grew impatient and made a golden calf.
Moshe's brother Aharon the high priest, cooperated in the making of the idol only to the extent that he thought that they would be delayed long enough for Moshe to return.
The women didn't participate in contributing to, or the making of the idol, and as a reward, G-d made Rosh Chodesh, the beginning of every month, a holiday for women.
Moshe finally comes down, sees what has transpired, and breaks the luchos. Rashi says that the luchos were like a marriage contract, and the idol worship was like adultery, so breaking the "marriage contract" made the "adultery" not quite as bad as if the marriage contract were still in force. Then Moshe appeals to G-d to be merciful to the Jews. G-d does forgive them, and assures them that they will be given the land flowing with milk and honey as originally promised their forefathers. However, G-d says that they will be lead by an angel and not by Him, as was done previously.
In the third aliyah Moshe asks G-d to reconsider the matter of the angel leading them. G-d reconsiders, and agrees to lead them Himself again.
In the fourth aliyah Moshe asks G-d, that if Moshe is finding favor in G-d's eyes at this time, may he request to be shown G-d's glory. G-d agrees, but limits what Moshe sees, to the extent Moshe is able to bear. G-d doesn't show Moshe His Face because no one can survive seeing G-d's Face. G-d says that Moshe will only see His Back. Rashi says the "Back" that Moshe saw was the knot of the tefillin of the head, that G-d wears.
Rabbi Shimshon Raphael Hirsch explains this concept as follows: the "Back" means that we often can not see Divine Providence in something that happens while it is happening, but we can see it later, when looking back at the situation.
In the fifth aliyah G-d tells Moshe to hew new tablets - luchos - from a sapphire quarry that was under Moshe's tent. G-d says that He will write the words that were on the first luchos on this second set of luchos.
Moshe goes up Mt. Sinai early in the morning, and G-d descends in a cloud, and Moshe proclaims the thirteen attributes of mercy.
Moshe said: "G-D - G-D", meaning merciful before the sin as well as after the person repents. "Erech apayim" - "long suffering", meaning slow to anger; G-d waits - perhaps the person will repent. Merciful to the 2000th generation, repaying iniquity to the fourth generation (Rashi points out that the attribute of mercy is 500 times greater than the attribute of punishment). This passage is recited daily in the confessional prayer tachanun (siddur p. 62) when we are asking for mercy for our sins, and also many times during Ne-ila prayer at the close of Yom Kippur.
The sixth aliyah continues the conversation of G-d and Moshe on Mt. Sinai. G-d says He will do wonders for the Jewish people driving out the nations of Canaan before them. G-d gives instructions to destroy the altars of those nations, and not to make any covenants with them.
G-d gives over various additional commandments. These include not making any molten gods, not to eat chametz on Pesach, and to sanctify the first- born male (pidyon haben) and cattle. Also given here: not to work on Shabbos, observation of the festival of Shavous, and finally, not cooking meat and milk together.
In the seventh aliyah G-d tells Moshe to write down all these words into the written Torah. Rashi points out that Moshe is not permitted to write down the oral Torah, which explains the written Torah.
Moshe was up on mount Sinai for 40 days and 40 nights without eating or drinking. When Moshe came down, beams of light were visible projecting off Moshe's skin, and Aharon and the people were afraid of him. (Rashi says these beams of light were from G-d touching Moshe's face.)
Moshe taught the people the words of Torah that Moshe heard on the mountain. Moshe wore a veil on his face when he talked to the people from that time on, but took it off when speaking to G-d.