He says, if someone forges a sanad.

In the Quran, and should I warn against him?

Because this is between him and his Lord, the Exalted. This is undoubtedly a lie.

But it does not fall under the one who lies about me.

Intentionally, but it is a lie. This is someone who pretends to have what he does not, like someone wearing two garments of falsehood.

So this is someone pretending to have what he does not, and there is no doubt that it is not allowed. A person claims to have a sanad but does not have one. However, we can warn people who learn the Quran from him.

We say this person, especially if he cannot recite the Quran properly.

We say, do not take the Quran from him because his chain of transmission is forged.

From this perspective, but just warning people, saying, "Watch out for so-and-so," there are many like this.

The forged certificate, look, they kept quiet about it, there's no talk about it now. For example, someone goes and talks about these people.

The point is that he should be advised, reminded of Allah the Exalted, but if someone asks you, for example, wanting to seek knowledge from him or recite the Quran to him, and you know his chain is forged.

And that he cannot even recite the Quran properly, then yes, you should warn against him.