What was Aharon thinking when he said "le'Mi Zahav"?
Seforno: He thought that when he asked them for gold, they would take a long time to respond, because they did not have anything ready.
How did Aharon excuse his actions?
Rashi #1: He explained to Moshe that all he asked them was who possessed gold, and they took the initiative by taking off their rings and bringing them to him. 1
Rashi #2, Seforno #1 and Targum Yonasan: He claimed that all he did was to throw the gold into the fire 2 and the Golden Calf emerged (Because the Satan emerged from the fire and made it - Targum Yonasan). 3
Seforno #2: Refer to 32:24:0.1:1. And he was caught by surprise when they took off their rings immediately.
How could Aharon say "Vayeitzei ha'Eigel ha'Zeh", which suggests that the Eigel had supernatural powers?
Megilah, 25b: From the fact that the Apikorsim did indeed extrapolate from Aharon's words that the Eigel possessed a spirit of life, Chazal warned that one should weigh one's words when making statements.