Aharon took all the gold that was collected and threw it into a fire to melt it. He still needed to stall for time… so he took an engraving tool and began to painstakingly carve out the image of an ox. (Pouring the melted gold into a mold would have been much faster and more efficient…)
A man named Micha, whose life was saved by Moshe when he was a young boy in Egypt, did his part to speed things along. He had in his possession a golden plate with the words Aley shor - "rise up, ox!" - inscribed on it, along with HaShem's holy name. These were the "magic words" that allowed Yosef's coffin to rise to the top of the Nile when the Jews were on their way out of Egypt. In fact, the tablet Micha held was the original gold plate that was used at that time.
Micha threw the golden plate into the fire, and out from the fire emerged a fully formed image of an eigel -- a young calf or ox. And to make things more confusing, the eigel moved!
