In fairness to the Qur'an, the chronological account given in Exodus is incredibly contradictory -- this is one of the main points where modern Biblical criticism was born, Exodus gives several different accounts of Moses getting the 'law' from Yahweh, and all of them conflict with each other in many details. Exodus even states two completely different versions of the 10 Commandments.
So the Qur'an's authors were understandably confused by the chaotic Exodus narratives about the law being given to Musa; if Exodus itself is incoherent on this point, why should the Qur'an have coherent chronology? Another Qur'anic example, in Surah 7:155 (right after the golden calf discussion, and after Musa delivers the ten tablets to the people), Musa randomly picks 70 men "for our appointment" who Allah then shakes (just terrifies? kills via earthquake? unclear, translations all differ) for no apparent reason, with no follow up explanation given. What is this doing here? Who are these 70 men anyways? Why is Allah terrifying/killing them?
Actually I think it surely comes from the 70 Hebrew elders identified in Exodus 24, which in the Biblical account precedes the golden calf narrative and the deliverance of the tablets; these 70 men, confusingly, not only are part of the delivery of the law to Moses, they actually see the God of Israel face to face, contradicting many other passages in the Bible. Because the Exodus 24 account conflicts with later accounts in Exodus, people do not usually remember this episode. Here it is. Note the incredibly contradictory chronology -- Moses is reading the narrative, and the people accept the law, and then AFTERWARDS he goes by himself up the mountain. This after the elders had all met with the God of Israel face to face, formed a blood covenant, and ate and drank with him. The entire narrative is awesomely composite and contradictory, and the rest of Exodus is just as bad.
https://www.biblegateway.com/passage/?search=Exodus+24The Qur'an seems uncertain about this Exodus chaos, as is understandable (who wouldn't be uncertain?), but nonetheless feels compelled to mention the 70 men and their earth shaking episode, now presented as some obscure parable about Allah's forgiveness; Allah could have killed the 70 men (for some unstated reason), but did not, and is therefore merciful. Why the earth shaking? I think it probably relates to 7:143, where Musa is rendered unconscious at his "appointment" by the shaking mountain that accompanies the revelation. In earlier contexts when these stories were told, the 70 men probably were understood to have been rendered unconscious along with Musa by Allah's earth-shaking revelation at the "appointment" mentioned in 7:143, since these 70 elders had accompanied Musa to see Yahweh consistent with the account in Exodus 24 (that is where they came from, after all). But the final Qur'anic narrative, losing the plot on the relevance of the 70 men, did not grasp how the 70 men fit in with Allah's revelation to Musa (now it is only Musa alone who met with Allah), so all that is left is a disconnected episode in which a random 70 men are shaken for no apparent reason after Musa took them to an 'appointment' that remains unclear and which came after Musa already delivered Yahweh's law -- thereby somehow illustrating Allah's forgiveness.
Topic: Worshipping a calf