To whom is Moses' command "then kill one another (lit. yourselves)" addressed?

Imām Ibn al-Jawzī (d. 597/1201) summarized the scholars' opinions in his book "Zād al-Masīr" as follows:

1. It was an address to all of them (to kill their own selves). [Al-Suddī]
2. It was an address to those who did not worship the calf to kill those who did worship. [Muqātil]
3. It was an address to the worshippers (of the calf) alone, commanding them to kill each other. [Abū Sulaymān al-Dimashqī]