As expected, the most important character in the story is "Mullah" As-Saamiri.
20:85 (God) said, "We have tested your people after you left them, and Saamiri has led them astray."
20:86 Moses returned to his people in a state of anger and sorrow. He said, “O My people! Did not your Lord make a good promise to you? Did, then, the fulfillment of this promise seem to you too long in coming? Or did you wish that your Lord’s requital come upon you, and so you broke your promise to me?”
20:87 They said, "We intended to break no promises. But this is what happened. We were loaded with the sinful burdens of the (Egyptians’) ornaments, and so we threw them into the fire, as suggested by this As-Saamiri."
20:88 Then As-Saamiri made the effigy of a calf. It even brought forth a lowing sound with wind or when blown into it. So they said, "This is your god, and the god of Moses, but he has forgotten.” [As-Saamiri was not a Sumerian. He originally hailed from northern India. Babu Rajindra’s treatise “Casting of a Caste” shows Saamiri belonging to India’s ‘Untouchables’. Fed up with apartheid, he tried to lay down the foundation of a new mixed caste that could socialize with all four castes of Hinduism. Consequently, he was exiled by the powerful Brahmins and ended up in Egypt and later followed Moses in the Exodus. Cow worship was running in his blood stream. Side by side, the golden calf of the Israelites symbolized the centuries old Egyptian influence. The Egyptians used to worship the ‘sacred’ bull APIS who was considered to be a god-incarnate. The soul of the sacred bull upon death was supposed to transmigrate into another idol called Osiris whom they worshiped as God’s son. Recall Uzayr mentioned in the Qur’an (9:30). Some Jews in Arabia, still under the influence of ancient Egyptian traditions during the times of the exalted Messenger, used to believe in Uzayr or Osiris the Bull-god as God’s son]
20:89 They knew full well that, like all false deities, the golden calf could not respond to queries, and had no control over their harm or benefit.
20:90 And Aaron had told them beforehand, “O My people! You are being tested in this idol. But your only Lord is the Beneficent! Follow me then, and obey my order!" [Exodus in the Bible 32:1-5, on the contrary, declares Prophet Aaron guilty of making and worshiping the calf!]
20:91 They said, “We will by no means cease worshiping it until Moses comes back to us.”
20:92 When he returned, Moses asked, “O Aaron! What stopped you when you saw them going astray?
20:93 That you followed me not? Didn’t you disobey my order?”
20:94 Aaron said, "O Son of my mother! Do not get mad at me, and do not treat me harshly. I feared that you would say, “You have let the Children of Israel divide into parties and sects." [Moses accepted this explanation since sectarianism is no less a crime than idol worship in any form. Seizing the beard and head pertains to harsh interrogation. 7:150]
20:95 Moses now turned to Saamiri, “What do you have to say O Saamiri?”
20:96 He answered, "I saw what they did not see. So I took a handful (of dust) from the footprint of the Messenger, and cast it away (into the calf). This is what my mind prompted me to do.”