Why is it not permissible to combine different narrations within a single verse, even though all narrations are authentic?

It is permissible to combine recitations (Qira'at) and narrations (Riwayat) according to the majority of the imams of recitation. However, they differed on the conditions for its permissibility. The majority permitted it absolutely, while others stipulated that the meaning or grammar should not be disrupted, or that one of the two recitations should not be dependent on the other in a way that corrupts the meaning. Some also emphasized that this should not be done by way of narration, for fear of deception and falsehood. Nevertheless, the common and preferred opinion is its permissibility, provided there is no mixing that leads to a change in meaning or a violation of the Arabic language.