What is the covenant that is referenced in this āyah?

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

1. It is the covenant He took from them to act on the Torah. They were reluctant to accept what was in it, so the mountain was raised over them. This was said by Muqātil. Abū Sulaymān al-Dimashqī commented, "They made a promise to Allah to act according to the Torah. When Moses brought it and they saw the heavy obligations it contains, they refused to accept it, so the mountain was raised over them."
2. It is the covenant that Allah took from the messengers and their followers to believe in Muḥammad (ﷺ). [via al-Zajjāj]
3. It could be the covenant taken from the progeny of Adam on the day they were taken from his back (see 7:172). [via al-Zajjāj]