We have omitted nothing in the Book.
[Wir haben nichts in dem Buch ausgelassen]
8:22 The worst of created beings in the Sight of God are the deaf and the dumb, those
who do not use their intellect. [2:18, 16:76]
6:38 -----We have omitted nothing in the Book (that was essential to be given through
Revelation.) Then to their Lord they will be gathered.
When we hear the words of the we have Quran to remember that Allah has sent those words to us. The Quran is the speech of Allah (swt), so Attention needs to be paid to every sentence. Every sentence puts the Message into perspective.
Allah (swt) has told us that He did not leave anything out of the Quran. When He tells us that it is complete it means just that. There is no other justification for it because when one studies the Quran, they learn that the message that the Quran is the Complete and Only Guidance is consistent.
We have been taught to accept many things that have been studied by honorable men that have been deceived into thinking that the information that they have been given for the Base of their studies is accurate. We are told in the Quran that it is complete and needs to be studied in context of itself, not outside of the Book unless we are observing the world, as we have been commanded to look at the creation and see if we can find any fault in it and if not then appreciate what Allah (swt) has blessed us with.
The only places where we are told that we need other sources to follow Islam , come from outside of the Quran. We need to think very carefully about this. Pay close attention to this. Why does the Quran tell it's reader that it's the only source for Islam and the sources that say that we need to follow anything but the Quran are from outside the Quran? Why?
People love Gossip , to know about everything about everything. We see it every day. People have always loved drama , its entertainment for them. Allah (swt) tells us that we cannot know about everything, only He knows. A true believer only needs a hint yet a denier will continue to deny until it's too late.
Stick to the Only source that has been authorized by Allah (swt) and THE Exalted Messenger [AS]. The Source of Righteousness. The Source of the Right Path. The Only source that needs to be followed in order to be heaven worthy.
Ref: Edited –One God One Message
16:89 ----- The Book We have revealed to you explains everything; a guide and mercy and the glad tiding for all those who have submitted. [Tibiyaanan likulli shaiy: The Book covers all things that were necessary to be revealed]
7:185 Can they not see (and correlate what he tells them, with) the Dominion of the
heavens and earth and what God has created? Does it ever occur to them
that the end of their own life may be near (hence the time to make the right
decisions is not unlimited)? In what Hadith after this (Qur'an) are they going
to believe then?
39:23 God has now revealed the best Hadith, a Book fully consistent within itself. It marks
out both ways (to success and failure) repeating its Messages in diverse forms.-------[4:88, 15:87. Hadith = Narration]
25:30 And the Messenger will say, 'O My Lord! These are my people who had abandoned
this Qur'an as something to be discarded.' ['Mahjoor' = Villagers tie one
fore foot of the cow with its horn so that it walks lame]
All other books are the books by ‘Club Of Criminals’.! They insult the Creator, Exalted Messenger[AS],his family members and the Sahabas. Period.
Bukahri [and his fellow friends] never existed . You may say there are thousand of books about him so do the Christians and Jews.
The Unpardonable Blashphemy against the Creator –Jibrael by mistake revealed the Quran to the Exalted Messenger[AS] instead of Hazrat Ali [RA] and  that the word Ali in the Quran is Hazrat Ali [RA].
Hint -Ayat ul kursi - aliyyul 'azeem. In Shia brothers home this is in bold or a shape of lion.