Uthman also said: “There are grammatical irregularities in the written Quran which the Arabs will rectify with their tongues.” He was asked, “Will you not change it?” He replied, “Leave it as it is, for it neither makes lawful what is unlawful nor makes unlawful what is lawful.” (1)
The majority of the Companions and scholars held that it is correct, though they differed over its explanation. It was said that it is in the accusative as an expression of praise. It was also said that it is in the accusative through an implied verb, the sense being: “I mean those who establish prayer,” and they are the ones who give zakah. It was further said that its grammatical position is genitive.
They differed over the manner of explaining this. Some said that its meaning is: “But those firmly grounded in knowledge among them, and those who establish prayer.” Others said that its meaning is: “They believe in what has been revealed to you and to those who establish prayer.” Then His words, “and those who give zakah,” return to the initial syntactic coordination: “and those who believe in Allah and the Last Day—those We shall give a tremendous reward.” Hamzah recited it, “He will give them,” with the letter yā’, while the others recited it with the letter nūn: “We shall give them.”
(1) Ibn al-Anbari states in his book al-Radd ala man khalafa Mushaf Uthman (Refutation of Those Who Opposed Uthman's Codex): “The reports narrated from Uthman concerning this matter do not constitute proof, because their chains are disconnected. Nor could any sound mind accept that Uthman, the imam of the community, its leader and exemplar in his time, would unite them upon the master codex, then discover a defect in it and observe errors in its script without correcting them. By Allah, no fair-minded and discerning person could imagine this of him, nor believe that he left an error in the Book for those after him to correct, when the course of those who came after him was to follow his orthography and abide by its ruling. Whoever claims that Uthman meant by his statement, ‘I see in it lahn (a grammatical error) . . .,’ that he saw an error in its written form which, when recited correctly, would not corrupt or alter the words or disrupt their grammar, is mistaken. For writing indicates pronunciation: whoever commits lahn in his writing commits it in his speech. Uthman would not have left any corruption in the spelling of the Quranic words, whether in writing or pronunciation. It is well known that he continually studied the Quran, had mastered its wording precisely, and approved what was written in the codices dispatched to the various regions and provinces.” See al-Itqan fi Ulum al-Quran by al-Suyuti, 2:322.