Sh'mot 32:1-6 Now when the people saw that Moshe delayed to come down from the mountain, the people assembled about Aharon, and said to him, "Come, make us a god who will go before us; as for this Moshe, the man who brought us up from the land of Egypt, we do not know what has become of him." And Aharon said to them, "Tear off the gold rings which are in the ears of your wives, your sons, and your daughters, and bring them to me." Then all the people tore off the gold rings which were in their ears, and brought them to Aharon. And he took this from their hand, and fashioned it with a graving tool, and made it into a molten calf; and they said, "This is your god, O Israel, who brought you up from the land of Egypt." Now when Aharon saw this, he built an altar before it; and Aharon made a proclamation and said, "Tomorrow shall be a feast to the L-RD." So the next day they rose early and offered burnt offerings, and brought peace offerings; and the people sat down to eat and to drink, and rose up to play.
The corresponding letter to this chapter is Yod - a metaphysical and Divine letter meaning hand - the right hand of G-d. Also Creation.
Aharon, who should know better, and was used as the High Priest, is the one who creates the golden calf. It's a sad thing when we fail HaShem. Especially when we remember all the good things He has done for us in the past. All the times He protected us from harm. He knows sometimes we fail Him. When this happens the right thing to do is to brush all the dirt off and get up again. Don't let your failures keep you from coming back to HaShem. We can still turn around and come boldly to the throne of mercy and receive forgiveness. We have a High Priest above who received temptation like we have but did not yield in to it. Don't let any Cohen, including the one that offers the animal sacrifices; keep you away from the ultimate sacrifice for our sins -that is Yeshua.
Hebrews 4:14-16 Seeing then that we have a great High Priest who has passed through the heavens, Yeshua the Son of G-d, let us hold fast our confession. For we do not have a High Priest who cannot sympathize with our weaknesses, but was in all points tempted as we are, yet without sin. Let us therefore come boldly to the throne of grace, that we may obtain mercy and find grace to help in time of need.
Sh'mot 32:7-10 Then the L-RD spoke to Moshe, "Go down at once, for your people, whom you brought up from the land of Egypt, have corrupted themselves. They have quickly turned aside from the way which I commanded them. They have made for themselves a molten calf, and have worshiped it, and have sacrificed to it, and said, 'This is your god, O Israel, who brought you up from the land of Egypt!'" And the L-RD said to Moshe, "I have seen this people, and look, they are an obstinate people. "Now then let Me alone, that My anger may burn against them, and that I may destroy them; and I will make of you a great nation."
HaShem is just and has to punish sin.
Sh'mot 32:11-14 Then Moshe entreated the L-RD his G-d, and said, "O L-RD, why does your anger burn against your people whom you have brought out from the land of Egypt with great power and with a mighty hand? "Why should the Egyptians speak, saying, 'With evil intent He brought them out to kill them in the mountains and to destroy them from the face of the earth'? Turn from your burning anger and change your mind about doing harm to your people. Remember Avraham, Yitzchak, and Israel, your servants to whom you did swear by yourself, and did say to them, 'I will multiply your descendants as the stars of the heavens, and all this land of which I have spoken I will give to your descendants, and they shall inherit it forever.'" So the L-RD changed His mind about the harm that He said He would do to His people.
Moshe again became their advocate. He is the type that points to our Messiah. Our Messiah, who is our advocate with the Father, keeps us from His wrath. There is nothing in us that stops His burning anger. He does it because of His Son.
Sh'mot 32:15-16 Then Moshe turned and went down from the mountain with the two tablets of the testimony in his hand, tablets which were written on both sides; they were written on one side and the other. And the tablets were G-d's work, and the writing was God's writing engraved on the tablets.
G-d creates the Ten Commandments written on both sides of stone. The number "ten" also fit with our corresponding letter.