“I will surely fill Hell with you and all those among them who follow you.”
He states that He will fill it with him and his followers. This shows that none will enter it except those who follow him. Thus, the unbelievers and sinful people who enter it are followers of Iblīs. It is well known that unbelievers are neither believers nor possessed of a knowledge of Allah that makes them believers.
Rather, the particle lām indicates the religious statement connected with His legislative will, as in His words, Most High:
“Allah intends ease for you and does not intend hardship for you.”
And His words:
“Allah intends to make things clear to you”—and the rest of the verse.
It may also indicate the outcome ordained in creation, as in His words:
“Whoever Allah wills to guide, He opens their heart to Islam”—and the rest of the verse.
This is like His words, Most High:
“They will continue to differ,”
“except those upon whom your Lord has mercy; and for that He created them.”
That is, He created some people for differing and others for mercy. He also says:
“We have certainly created for Hell many of the jinn and humans.”
Thus, the particle lām in His words, Most High,
“I did not create jinn and humans except to worship Me,”
even if it is the same lām as in this verse, signifies the agent’s will and purpose. Hence, in the Book of Allah, this will is divided into religious will and will governing creation. Likewise, in the Book of Allah Most High, words, commands, judgments, decrees, prohibitions, permissions, and other such expressions fall into these two categories.
Furthermore, Allah Most High says:
“O assembly of jinn and humans, did there not come to you messengers from among yourselves, relating My verses to you and warning you of the meeting of this Day of yours?”
through to His words:
“And they testified against themselves that they