Chp. 32 verses 4 - 15: Aaron took their gold and fashioned a golden calf. He then built an alter, and the next morning they brought sacrifices to the calf and worshiped it. G-d told Moshe to descend from the mountain since the people had sinned. Hashem threatens to destroy the nation but Moshe pleads with Him not to do so, and Hashem agrees to not destroy them. Moshe then comes down the mountain with the two tablets in his hand.