פּירוש אויף שמות 32:24

ואמר להם AND I SAID UNTO THEM one single thing, — simply, “Who has any gold?” — but they hastened and broke it off from themselves and gave it to me.

ויצא העגל הזה, “this calf emerged;” it came out complete. We find a similar wording in Proverbs 25,4: ויצא לצורף כסף, “and it emerged for the silversmith as a silver vessel.” Aaron threw into the crucible assorted pieces of golden jewelry, and what emerged from the crucible was a fully formed golden calf.

ויצא העגל הזה, “and this calf emerged (from the crucible)” Apparently, when Aaron used his graving tool the gold was inside some sort of mould, and it emerged all at once (not as molten gold.) According to some opinions, Aaron had thrown in a golden sheet that had been used to transport Joseph’s coffin, Joseph had been referred to by Yaakov in his final blessings as an ox so that somehow this sheet responded to the call; “arise ox!” (Tanchuma section 19 on our portion)

ואשלכהו באש AND I CAST IT INTO THE FIRE, and I did not know that this (i. e. this living) calf would come out, ויצא — BUT IT DID COME OUT.