Why did Moshe need to see the Eigel? Had Hashem not already told him about it?
Oznayim la'Torah #1: Hearing is not comparable to seeing, which makes a more powerful impression on a person. Consequently Moshe's anger was amplified when he ctually saw the people worshipping the golden calf and he decided to break the Luchos.
Oznayim la'Torah #2: When Moshe saw that it was not just a matter of bowing down to an idol but dancing with joy - and simultaneously commiting adultery and murder, he realized that they would not do Teshuvah, even when they saw the miracles that surrounded the two Luchos, 1 which would not stop them from the path that they had taken - and that they therefore needed to be broken.
Oznayim la'Torah #3: Moshe actually brought down the Luchos with the expresss intention of breaking them before the eyes of the people. 2 m
What did Moshe see?
Da'as Zekenim and Rosh: He saw that the letters [of the Aseres ha'Dibros] flew off the Luchos. Therefore, he grabbed them and broke them in front of Yisrael's eyes.
Oznayim la'Torah: He saw the second thing that Hashem referred to when he stood before Him by the burning bush. 1
Refer also to 9:16:1:1 &2.
