Compared to all other scriptures, the Qur’an is the best preserved in both the hearts of Muslims and the written copies of the codex (muṣḥaf)—a manifestation of Allah’s promise to protect Divine revelation from distortion:

Indeed, it is We who sent down the Qur’an and indeed, We will be its Guardian.¹

https://yaqeeninstitute.ca/read/paper/how-the-quran-was-preserved-during-the-prophets-time-mechanisms-of-oral-and-written-transmission