The Ohr Hachaim explains the possuk in detail. The people saw, with the mind’s eye. They could not see Moshe’s delay with their eyes. However, Chazal say that the devil came and showed them the form of darkness and gloom, as well as the coffin of Moshe Rabbeinu. The reason they saw this is כ יִ בֹשֵׁשׁ – that the sixth hour had come באִשש. Moshe was supposed to have descended from the mountain already, and the confusion caused them to believe the lies of the devil.
Then the nation congregated on Aharon. The Torah says that they congregated on him, not that they congregated and spoke to him. It is possible that the Torah means that they gathered to kill him. The Gemara writes that they killed Chur for his refusal to fashion an idol for them.
The Torah does not wish to write this story clearly, in order that their indiscretion not be eternalized in the Torah. The only reason the Torah describes the story of the Golden Calf is to teach future generations about the possibility of Teshuva. If Klal Yisroel ever sins communally, they can know that Teshuva is still possible; all is not lost.
But the Torah does allude to Chur’s death. At the end of Parshas Mishpatim, when Moshe rises up the mountain to learn Torah from Hashem, he told Klal Yisroel וְה נֵּהִאַהֲרֹןִוְחוּרִע מ כֶם - behold, Aharon and Chur are with you. Yet, when Klal Yisroel wished to make a Golden Calf, they turned only to Aharon. What happened to Chur? This alludes to that which Chazal revealed that Chur was killed by the mob.
The Ohr Hachaim adds another point. When the rabble heard Chur refusing to build a Golden Calf for them, they suspected him of having secret plans for himself. They thought that he wished to inherit Moshe’s post, standing between Klal Yisroel and Hashem. They specifically wished to have a calf and not a person. A human being has free will and personal wishes and whims. If he is to stand between Klal Yisroel and Hashem, they could not trust that everything he told them was directly from Hashem. When they suspected Chur of wanting the job for himself, they killed him. They did not want any human pretenders to this position.
The request continues with אֲשֶׁרִיֵלְכוִּלְפ נֵינוּ - who shall go before us. They were saying that Hashem, who removed them from Mitzrayim, was too high and removed from their understanding. They needed something that was close to their understanding, something that was part of this world. They were not rebelling against Hashem, they merely wanted something to bridge between them and Him. That is why they said ‘before us’. They wanted someone on their level.
Their proof was that Moshe, who took them out of Mitzrayim, was also a person who served as a bridge between Klal Yisroel and Hashem.
This was a great mistake, Klal Yisroel did not need anything between them and Hashem. Our connection with Hashem is personal, not through any go-between.
