Parshat Mishpatim

After a lengthy list of laws and statutes, the Torah portion returns to the narrative of the Jews standing at the foot of Mount Sinai. G-d tells Moshe, "Behold I will send my angel to go before you, to guard you on the way, and to bring you to the place which I have prepared" (Exodus 23; 20). Rashi explains that G-d here warns Moshe and the people that they will come to sin with the Golden Calf, and instead of G-d leading them directly, He will direct the nation through the intermediary of an angel. This is what we find in the Torah after the sin of the Calf, G-d says to Moshe, "Now go and lead the people, to that which I spoke to you. Behold my angel will go before you..." (ibid. 32; 34).
We have a principle that Heavenly punishment always fits the crime, and this is indeed the case here. At the time of the Golden Calf the nation were afraid that Moshe had been killed, and would not return. Therefore they wanted another leader, to act as an intermediary between them and G-d. They said to Aharon, "Make for us a god (or judge) that will go before us, for this man Moshe, who brought us out from the land of Egypt, we know not what has become of him." (ibid. 1). They did not consider Moshe divine, rather a leader who was an intermediary between them and G-d. Similarly the concept behind the Calf was for to have an intermediary, not a god. Only after it was built did some of the people begin to worship the Calf itself, and proclaim it as a god.
However, even asking for an intermediary deserved punishment. When the people heard G-d at Mount Sinai they were afraid, and asked Moshe, "'You speak to us and we shall hear; let not G-d speak to us lest we die'. Moshe said to the people, 'Do not fear, for in order to elevate you has G-d come...'" (ibid. 20; 16-17). Moshe rebuked the people for not wanting this direct contact with G-d. In fact we find that the desire for intermediaries was the origin of idolatry in the world. The Rambam writes (Yad, Laws of Idol Worship, 1; 1) that in the generation of Enosh the people made a grievous error. They reasoned that it was not appropriate to pray directly to G-d, but they should instead pray to Him via the celestial luminaries that He had placed before him. Over the generations this led to forgetting that these were only intermediaries, and the people began worshipping them as gods.
So, from the outset, the building of the Golden Calf was bound to end in disaster. Though the Jews were only seeking an intermediary, that was itself a sin that would inevitably lead to idolatry. Therefore as punishment G-d told them that He would not be in their midst, but would only relate to them through an angel.
The Ramban points out that this punishment of 'I will send an angel before you' never took place. Moshe pleaded for mercy, "If Your presence will not go with us, do not take us out from here..." (ibid. 33; 15), and G-d consented when He said, "I will also do this thing that you have spoken" (ibid. 17). Although this decree did not take place in Moshe's lifetime, it was fulfilled immediately after his death. Just before Yehoshua led the nation to do battle with Jericho the Bible states, "And it came to pass, when Yehoshua was by Jericho, that he lifted up his eyes and looked, and behold there stood a man over him, and he said, 'I am captain of the host of the Eternal, I am now come'." (Joshua V; 13-14). The Midrash Tanchuma (Mishpatim 18) explains: "The angel said to Yehoshua, 'I am he who came in the days of Moshe your master, and he pushed me away and did not want me to go with them.'". After Moshe's death, G-d's relationship with the nation changed, from being direct, to being only through an intermediary.
Nevertheless, it seems strange that the Israelites were punished for wanting an intermediary, when at the end of this week's Torah portion we find that they are not able to cope with direct revelation. "Go up to G-d, you [Moshe], Aharon, Nadav and Avihu, and seventy of the elders of Israel, and you shall prostrate yourselves from a distance, Moshe, Aharon, Nadav and Avihu, and seventy of the elders ascended. They saw the G-d of Israel, G-d did not stretch out His hand [to punish] the great men of Israel - they gazed at G-d, yet they ate and drank." (Exodus 24; 1-11). Rashi explains that G-d did not punish them on the spot, though they were worthy of punishment for gazing at Him. However, G-d delayed their punishment so as not to detract from the sanctity of Mount Sinai. The reason that they were punished was for staring at G-d while they were eating and drinking. They were unable to attain the proper level of spirituality but instead were sunk in their material actions. We see from here that even the leaders of the Israelites, with the exception of Moshe and Aharon, were unable to cope with such a direct relationship with G-d. Why then were they punished for wanting an intermediary?
The answer must be that their need for an intermediary was real, and thus their attempt to find one valid. However, their mistake was in settling for this lesser relationship with G-d instead of trying to elevate themselves spiritually to a level where they would be able to sustain a direct relationship. As long as they were in the desert, under the influence of Moshe, they were able to have G-d's presence in their midst. But as soon as Moshe was no longer with them, instead of remaining on this spiritual level the people settled for intermediaries to lead them. The angel coming was not so much a punishment as it was the inevitable result of the people's actions and spiritual level.