the meaning of the Quran by interpreting its verses in accordance with their own opinions and their heretic tendencies.
There are prophetic statements prohibiting such alteration of the meanings, and the doer of these alterations has been condemned in a number of traditions. Among these traditions is the one reported by al-Kulayni, whose chain of transmission goes back to the Imam MuQ.ammad al-Baqir (peace be upon him), who wrote in his letter to Sad al-Khayr:

Among their ways of repudiating the Book [of God] is that they stand by its wording, whereas they misconstrue its limits. Hence, they see it but do not submit to it. And the ignorant ones are pleased with their memorization of the text, while the learned are grieved by their leaving obedience to it.١

Second; the word ta/.zrifhas also the sense of "an omission or addition in the let‌ ters or the vocalization [of a word], while the Quran remains preserved [in its mean‌ ings] and without loss [of any part], even if [the altered words] were not distinct from others."
Alteration in this sense definitely occurred in the Quran. Earlier in this book, we
demonstrated that the readings of the Quran have reached us through an uninter‌ rupted transmission. This means that the revealed Quran accords with only one of the [ten preserved] readings, while the rest contain additions or omissions.
Third, the word tal.zrifis used in the sense of "the omission or addition of a word or two, while the revealed Quran remains preserved [in its meanings]."
Alteration in this sense occurred in the early days of Islam, and definitely during the period of the Companions. The evidence of this is the consensus among Muslims that Uthman ordered his governors to bum all the codices except the one codex that was collected under his orders. This shows that these [destroyed] texts were different from the one that was officially compiled; otherwise, there was no justification to de‌ stroy them. Some scholars have recorded the instances that had occasioned differences among these codices. One of them was AbdAllah b. AbiDawild al-Sijistani, who named his workKitab al-Ma$li/.zif(The Book of the Codices [of the Quran]). Thus, there is no doubt that alterations were made either by Uthman or by the scribes of the destroyed codk-es. However, we shall explain that what was compiled under Uthman was the Quran that is now known among Muslims, which had passed to them, successively, from the Prophet (peace be upon him and his progeny), hand to hand. The addition and omission had occurred in those other codices that were discontinued after Uthmans reign. As for this existing Quran, there is no addition or omission in it.
In short, for those who maintain that the transmission of those other codices has stopped-which is actually the case-tal.zrifin this third sense did occur in the early days of Islam, but it certainly ended during the reign of Uthman, and the text was restricted to the one whose uninterrupted transmission from the Prophet was estab‌ lished. As for those who maintain that all the codices continued to be transmitted without interruption, they have to accept the corollary that alteration in the sense that Muslims are not in agreement upon would have occurred in the revealed Quran, and that part of it is lost. We noted the statements of al-Tabari and other scholars regard‌
ing Uthmans abolition of the six other barfs in which the Quran was revealed, and
restricting it to only one.٢