Al-Mutaffifin 83:32 - Linguistic Miracle

And when they saw them, they would say, “Indeed, those are truly lost “

Dual use of emphasis by using إن and Lām together, which as explained earlier, is

used when addressing someone who does not believe in what you are saying to him. This verse is not simply denoting their speech to others, but their effort in trying to convince other people, as well as the believers, that they are upon falsehood, and hence they should leave Islam, and stop prohibiting worldly pleasures and luxuries upon themselves which Islam forbids on them.