Does the verse: "And if you are in doubt concerning what We have sent down upon Our servant, then produce a surah of the like thereof" refer to "Our servant" or "His servant"? And why was it not: "And if you are in doubt concerning what was sent down upon His servant, then produce a surah of the like thereof"? And does the verse: "And recite what has been revealed to you from the Book of your Lord. There is no changer of His words, and never will you find, besides Him, any refuge" refer to a change in the words of Allah during the revelation and a command to whoever changed the words?

The first verse, "{And if you are in doubt about what We have sent down upon Our servant, then produce a surah (definition) the like thereof and call upon your witnesses other than Allah, if you should be truthful}" is the word of Allah, and the plural pronoun is for magnification. The second verse, "{And recite what has been revealed to you from the Book of your Lord. No one can alter His words, and you will not find any refuge other than Him}" does not imply alteration in the words of Allah, but rather asserts its negation, and that the words of Allah are truthful in information and just in rulings.