Salamun 'alaika br. Joseph!
Traditionalists sometimes use 9:100 to "authorize" ahadith, they claim:
Why don't we have any record of early Muslims completely rejecting hadith?
The hadith rejecter might argue back by saying "we don't blindly follow people; you are committing the appeal to tradition fallacy".
However, you answer back that Allah says in the Quran...
Surah 9:100
The vanguard (of Islam)- the first of those who forsook (their homes) and of those who gave them aid, and (also) those who follow them in (all) good deeds,- well- pleased is God with them, as are they with Him: for them hath He prepared gardens under which rivers flow, to dwell therein for ever: that is the supreme felicity.
In this verse, Allah is saying that the Muhajirin (those who migrated from Mecca to Medina) and the Ansar (the people of Medina) and those righteous people that came after them have been promised heaven.
Now, how can Allah promise heaven to these people when they are the very same ones who transmitted the hadith to us? As a matter of fact they are the same people that passed the Qur'an down to us. The Quran is passed on to us by "Mutawattir" narrations. Mutawattir narrations are narrations that have been transmitted by so many people that it would be impossible for all of the transmitters to fabricate such a narration. However, we have an enormous amount of Mutawattir hadith. We have a list of Mutawatir hadith
http://hadith.al-islam.com/bayan/Index.asp?Lang=ENG&Type=3 that teach things that are not taught in the Quran. How can you reject their authenticity with no objective evidence?
If we are expected to believe that ALL the Muslims could have corrupted Islam by introducing the Hadith then to maintain consistency we must also conclude that it was very likely for them to have corrupted the Qur'an as well. The Hadith rejecter will respond back by saying that Allah promised to preserve the Qur'an (Surah 15:9) but not the hadith. However, this is circular reasoning. The Hadith rejecter is basically saying "The only evidence that the Qur'an is preserved is that the Qur'an says so." No objective person will take such an answer seriously.
Source:
http://www.call-to-monotheism.com/questions_that_the_quranites_have_no_good_logical_responses_toWasalaam!