That is because they say, "Never will the Fire touch us except for [a few] numbered days,"
ذلك بأنهم قالوا لن تمسنا النار إلا أياما معدودات [Ali 'Imran 3:24]
that
ذلك
The reference is to their turning away and rejection, for they deceived themselves and said, "The Fire will not touch us," meaning it will not afflict us, "except for a few counted days," a small number of days, because everything that is counted is few. The evidence for this is the saying of Allah the Exalted:
And what We delay it for is for a counted term
وما نؤخره إلى لأجل معدود
And He said:
Say, The enjoyment of this world is little
قل متاع الدنيا قليل [An-Nisa 4:77]
So everything that is counted is few, because anything that passes—whether one, two, three, or four—must come to an end. These people say:
Never will the Fire touch us except for [a few] numbered days
لن تمسنا النار إلا أياما معدودات [Ali 'Imran 3:24]
Then who will succeed them after them? Who will succeed them in it? They claim that the one who will succeed them is the Prophet (peace and blessings be upon him) and his Companions, and these are the Jews, a claim from them that is refuted. They said: "They will enter the Fire, but they will not remain in it except for a few counted days, and then the Prophet (peace and blessings be upon him) and his Companions will succeed them in it forever, the ages of ages." They lied in this, so the Fire will touch them and they will remain in it forever, the ages of ages. But they deceived themselves and deluded the common people with this fabricated statement.
That is because they say, "Never will the Fire touch us except for [a few] numbered days," and [because] they were deluded in their religion by what they were inventing.
بأنهم قالوا لن تمسنا النار إلا أياما معدودات وغرهم في دينهم ما كانوا يفترون [Ali 'Imran 3:24]
"Deluded them" (gharrahum) means delusion and deception; the two are close in meaning. It means these people deceived, or were deceived, in their religion, where they thought they were in the right, while some of them defied the truth while knowing it, fabricating and lying. "What they used to fabricate deluded them in their religion" means what they used to fabricate. Among this is their saying:
Never will the Fire touch us except for [a few] numbered days
لن تمسنا النار إلا أياما معدودات [Ali 'Imran 3:24]
. Shall we take the benefits in the future or now? Yes.