On the 17th of Tammuz Moses broke the first tablets upon which were engraved Ten Commandments that he had received on Mount Sinai. Centuries later, the daily sacrifice in the first Temple ceased. Still later, in the times of the second Temple the walls of Jerusalem were breached by the Romans. It was also the date on which the wicked Apustumus burned the Torah and put an idol in the Temple. Because of all these tragedies, our Sages declared the 17th of Tammuz a fast day, which it remains until the Final Redemption wipes away all suffering forever.
The entire Jewish people had gathered around Mount Sinai to receive the Torah from the Creator. But after that awesome event, Moses again ascended the Mount to learn all the details contained in the Torah and to receive the Tablets of the Covenant.
Before he left he instructed the people, "At the end of forty days, at the beginning of the sixth hour, I will return to you and bring you the Torah." The people were very strongly attached to their leader, the faithful shepherd who had brought them out of Egypt and sustained them throughout all their travails.
As soon as he left they began calculating his return. They assumed that the day on which he ascended the Mount was to be considered the first of the forty days. But, that day was actually to be considered only a partial day, with the full forty days ending only on the 17th of Tammuz.
When the 16th of Tmamuz arrived Moses had not returned. The Evil Inclination came and asked, "Where is your teacher Moses?"
"He has ascended the mountain," they replied.
"No," said the Deceiver: "He is dead."
But they refused to pay any attention to him. He wouldn't desist, and tried another ploy: "Six hours have already passed," he taunted them. Still, they ignored him. But when the Great Deceiver showed them an image of Moses lying on his death bed, they succumbed.
Since their faith in Moses was far deeper than anything they could perceive with their own intellect, they were completely shaken when it seemed that his words had not come true.
Their attachment and love for Moses was so intense that they were unable to exist without him even for a short while. They ran to Aaron and cried, "Make us a god!"
How could people who had just witnessed the most stunning event in human history succumb to such a craze? How could the same people who had just witnessed Divine revelations and heard the Voice of G-d beg for an idol?
But the entire nation did not fall into this snare. They had split apart into numerous factions, each confident of its own viewpoint.
Aaron thought he would delay them. "Ask you wives for their gold jewelry, otherwise I cannot construct a calf," he told them.
When the women heard the plan, they wanted nothing to do with the idol. The men, however, were determined to proceed and donated all their gold.
Aaron dared not delay the mob any longer. The hotheads amongst them were becoming violently agitated, and nothing would stand in their way. Aaron took the gold and threw it into the fire. To his surprise a golden calf leaped out, for sorcery was honed to a fine art in Egypt, and among the numerous Egyptians who had followed the Jews into the desert were expert practitioners of the black arts.
When they saw the calf some found the attraction of idol worship too overwhelming to resist. After all, hadn't they been immersed in Egyptian "culture" for hundreds of years?
There was another faction which was mildly inclined to idol worship, but suppressed their desire for it after having witnessed the events at Sinai.
They looked from the sidelines with vicarious pleasure as the others danced wildly around the calf.
Still others were shocked at what they saw. To them all the other factions seemed absurd, both those who worshipped the calf and those who merely watched on the sidelines. They said, "One faction is as evil as the other." Yet, another group never lost faith. When they saw the actions of the other groups, they said, "They will never be able to repent.
Let's divorce ourselves from them completely!" This attitude was in itself a sin, for they should not have abandoned all hope for their erring brethren.
The following day when Moses descended the mountain, bearing aloft the Tablets, what a scene met his eyes! Love of the Jews ever foremost in his mind, he immediately thought, "How can I give them the Law? It says 'Thou shalt have no other gods,' and now they will be subject to the death penalty.
When Moses turned around to leave, the holy letters on the Tablets flew away. When that happened, the weight of the stones became too great for him (for the words themselves had carried the Tablets), and he dropped them.
The Levites, the one group which had in no way taken part in the calf-worship, rallied to Moses like a loyal army.
Punishment was meted out to the guilty, but through this experience, the vast majority of the people became forever rooted in their belief and trust of Moses and G-d.
The sin of the Golden Calf proved for all generations that repentance is always possible, for even the worshippers of the Golden Calf, in the end, returned to G-d.
