Prophet's Only Duty
The Quran utilizes "the double negative" to emphasize that the prophet had NO duty EXCEPT delivering the Quran.
[42:48] You have NO duty EXCEPT DELIVERING the message.
[13:40] Your ONLY duty is delivering, we will call them to account.
[5:99] The messenger has NO function EXCEPT delivery of the message.
THE QURAN IS THE MESSAGE
[21:10] We have sent down to you a scripture containing YOUR MESSAGE. Do you not understand?
MARMADUKE PICKTHALL'S TRANSLATION :
"Thine is ONLY to convey (the message)." 42:48
"..thine is BUT conveyance (of the message)." 13:40
"The duty of the messenger is ONLY to convey (the message)" 5:99
"Now we have revealed unto you a Scripture wherein is YOUR REMINDER." 21:10
PROPHET MUHAMMAD FORBIDDEN FROM ISSUING RELIGIOUS
INSTRUCTION OTHER THAN THE QURAN
[69:40-46] This is the utterance of an honorable messenger. Not the utterance of a poet; rarely do you believe. Nor the utterance of a soothsayer; rarely do you take heed. A revelation from the Lord of the universe. Had he uttered any other teachings. We would have punished him. We would have stopped the revelations to him.
PROPHET MUHAMMAD FORBIDDEN FROM
EXPLAINING THE QURAN
[75:16-19] Do not move your tongue to hasten it. It is we who will collect it into Quran. Once we recite it, you shall follow such a Quran. Then it is WE who will explain it.
GOD - TEACHER OF THE QURAN
[55:1-2] The Most Gracious. Teacher of the Quran.
QURAN - FULLY DETAILED AND ONLY
SOURCE OF RELIGIOUS LAW
[6:114-115] Shall I seek other than GOD as a source of law, when He has revealed to you this book fully detailed? Those who received the scripture recognize that it has been revealed from your Lord, truthfully. You shall not harbor any doubt. The word of your Lord is complete, in truth and justice. Nothing shall abrogate His words. He is the Hearer, the Omniscient.
[10:37] This Quran could not possibly be authored by other than GOD. It confirms all previous messages, and provides a fully detailed scripture. It is infallible, for it comes from the Lord of the universe.
OBEYING THE PROPHET IS UPHOLDING
THE QURAN ONLY
Prophet Muhammad obviously was a believer, and as a believer he followed the above verses from the Quran, which came from his own mouth. Now that Muhammad is dead, obeying him is upholding what he upheld. To suggest that Muhammad violated the above verses, by issuing religious laws or following other sources besides the Quran (like the insistence on hadith/sunnah), is to say that Muhammad was a disbeliever.
DEAD, NOT ALIVE
God in His infinite Wisdom, has clarified the meaning of DEAD, a meaning the idolators cannot comprehend. Muhammad is dead. How can you obey a dead man?
[16:21] They are DEAD, NOT ALIVE, and they have no idea how or when they will be resurrected.
[25:58] You shall put your trust in the One who is Alive - the One who never dies - and praise Him and glorify Him. He is fully Cognizant of His creatures' sins.
[17:46] We place shields around their minds, to prevent them from understanding it, and deafness in their ears. And when you preach your Lord, using the Quran alone,* they run away in aversion.
[25:30] The messenger said (on the Day of Judgment), "My Lord, my people have DESERTED this Quran."