What does « Lḥad » mean in the Quran?

And to Allah belong the best names, so invoke Him by them. And leave [the company of] those who practice deviation concerning His names. They will be recompensed for what they have been doing.

And We certainly know that they say, "It is only a human being who teaches the Prophet." The tongue of the one they refer to is foreign, and this Qur'an is [in] a clear Arabic language.

And recite, [O Muhammad], what has been revealed to you of the Book of your Lord. There is no changer of His words, and never will you find in other than Him a refuge.

Indeed, those who have disbelieved and avert [people] from the way of Allah and [from] al-Masjid al-Haram, which We made for the people - equal are the resident therein and one from outside; and [also] whoever intends [a deed] therein of deviation [in religion] or wrongdoing - We will make him taste of a painful punishment.

Indeed, those who inject deviation into Our verses are not concealed from Us. So, is he who is cast into the Fire better or he who comes secure on the Day of Resurrection? Do whatever you will; indeed, He is Seeing of what you do.