Most High says:

“He has sent down the best of speech.”

The Prophet, may Allah bless him and grant him peace, said to Ubayy, “Do you know which verse that you know from Allah’s Book is the greatest?” He also said, “I shall certainly teach you a surah the like of which has not been revealed in the Torah, the Gospel, the Psalms, or the Quran.” There are other examples already mentioned.

Some of them said: Rather, what is meant by His words “better than it” is “better for you”—that is, bringing greater reward or involving less hardship. They said that whatever indicates that some of it is more excellent than the rest does not establish the superiority of the speech itself, but of what relates to it: reciting this passage and acting upon it brings greater reward than reciting and acting upon another.

The response to these people is: What you have mentioned is evidence against you, besides contradicting the text. For the reward for one of two utterances or deeds is greater than that for the other only because it is intrinsically more excellent. This is why the texts speak of the excellence of the utterance or deed itself. The Prophet, may Allah bless him and grant him peace, was asked on more than one occasion, “Which deed is most excellent?” He would answer by declaring one deed superior to another, which necessarily entails its greater reward. As for a greater reward when the two deeds are equal, this is contrary to both revelation and reason.

The same applies to speech. In Sahīh Muslim, Samurah reports that the Prophet, may Allah bless him and grant him peace, said:

“The most excellent utterances after the Quran are four—and they are part of the Quran: Glory be to Allah; praise be to Allah; none has the right to be worshipped but Allah; and Allah is the Greatest.”