And now that We replace one message by another
125 - since God is fully aware of what He bestows from on high, step by step
126 - they [who deny the truth] are wont to say, "Thou but inventest it!" Nay, but most of them do not understand it!
127
Asad Translation Note Number :
I.e., by substituting the message of the Qur'an for the earlier dispensations-and not, as some Muslim scholars maintain, "abrogating" one Qur'anic verse and replacing it by another. (Regarding the untenable "doctrine of abrogation", in the latter sense, see {2: 106} and the corresponding note [87]; see also note [35] on {41: 42}.)
I.e., the gradualness of revelation (implied in the verbal form yunazzil) corresponds to God's plan, according to which He has gradually unfolded His will to man, substituting one dispensation for another in the measure of mankind's intellectual and social development, bringing it to its culmination in the message of the Qur'an.
I.e., they do not understand the necessity of a new dispensation and, therefore, do not really understand the Qur'an.