What is the etymology of the name Iblīs?

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

1. It is a name not derived from any Arabic root, and therefore it is not declinable (does not take the usual case endings in Arabic). [Abū ʿUbaydah, al-Zajjāj, Ibn al-Anbārī]
2. It is derived from al-iblās which means despair. [Abū Ṣāliḥ, Ibn Qutaybah]