The Women - 4:153
"The people of the Book ask you to send down to them a Book from the sky. They had asked Moses for something greater than that and said, "Show us Allah physically". They were struck by lightning because of their transgression. They served the calf even after clear proofs came to them. Again We forgave them, and We gave Moses a clear authority."
That those who serve the calf should ask forgiveness and be forgiven:
The Cow/2:54
"Moses said to his people: "O My people, you have wronged your nafs (personality, essence, soul) by worshipping/serving the calf. Repent to your Creator and kill your nafs (ego). This is better for you in the sight of your Creator."He will forgive you. Surely He is the Accepter of repentance, the Most Merciful."
The Heights/7:148
The people of Moses made after him a calf of ornaments, a calf with a roar, and idolized it. Did they not see that it was incapable of speaking and guiding them? They became of the wrongdoers by adopting it.
The Heights/7:149
"When they regretted what they had done and realized that they had gone astray, they said: "If our Lord does not pity us and forgive us, we shall be losers"."
The Heights/7:150
"When Moses returned to his people, angry and disappointed, they said, "What evil deeds you have done after me! Have you not been able to endure the command of your Lord?"He threw down the plates, grabbed his brother´s head and pulled him towards him: "Son of my mother,"he said, "these people have taken advantage of my weakness, and they almost killed me. Do not make the enemy laugh by coming upon me, and do not associate me with this cruel people."
The Heights/7:151
"(Moses) said: "My Lord, forgive me and my brother. Have mercy on us. You are the most merciful of the merciful."