Is the Arabic letter sacred, and is the Maliki school's opinion on this correct?

The Maliki school views as unlawful the act of Istinja' (cleansing with water) and Istijmar (cleansing with stones or similar) with anything written in the Arabic language, whether it be Quran, Hadith, or anything else, out of reverence for its letters; because it is the language of the Quran. As for other uses, they differentiate between revered and non-revered speech, prohibiting the desecration of the former and disliking the desecration of the latter. Meanwhile, the majority of scholars believe that reverence applies to what is written with Arabic letters, not to the letters themselves. Therefore, Istijmar is not prohibited unless the written material is something revered, such as Quranic verses, Hadith, or the names of Allah and the Prophets.