A quick Google of the narration:
Saheeh Bukhari
Volume 8, Book 82, Number 816:
Narrated Ibn 'Abbas:
'Umar said, "I am afraid that after a long time has passed, people may say, "We do not find the Verses of the Rajam (stoning to death) in the Holy Book," and consequently they may go astray by leaving an obligation that Allah has revealed. Lo! I confirm that the penalty of Rajam be inflicted on him who commits illegal sexual intercourse, if he is already married and the crime is proved by witnesses or pregnancy or confession."Sufyan added, "I have memorized this narration in this way." 'Umar added, "Surely Allah's Apostle carried out the penalty of Rajam, and so did we after him."
Saheeh Muslim
Book 017, Number 4194:
'Abdullah b. 'Abbas reported that 'Umar b. Khattab sat on the pulpit of Allah's Messenger (may peace be upon him) and said: Verily Allah sent Muhammad (may peace be upon him) with truth and He sent down the Book upon him, and
the verse of stoning was included in what was sent down to him. We recited it, retained it in our memory and understood it. Allah's Messenger (may peace be upon him) awarded the punishment of stoning to death (to the married adulterer and adulteress) and, after him, we also awarded the punishment of stoning, I am afraid that with the lapse of time, the people (may forget it) and may say: We do not find the punishment of stoning in the Book of Allah, and thus go astray by abandoning this duty prescribed by Allah. Stoning is a duty laid down in Allah's Book for married men and women who commit adultery when proof is established, or it there is pregnancy, or a confession.
Brother, the above narrations clearly claim that the verses were first introduced as part of the Koran, and yet was removed afterwards.
Brother, I have been taught about the Rules of Nasikh wal Mansuh in a Madrasah before, a Madrasah with strong inclinations towards the Wahabbi movement (although they dislike using the term on their ownselves). I know this hadith.This Hadith forms the basis of one of the few 'types' of abrogation. I have been taught of all these and more during one of our lessons on Nasikh wal Mansuh. Even back then, even when I was still in Secondary school, I had difficulty in understanding why this verse was supposedly left out of the Koran ,and yet, its inhumane ruling still exists.
And yet, the answer from my teachers were all the same. "We hear, and we obey". So the question arises, what if you have heard wrongly?
We believe that only God is infallible, and yet we ascribe almost godly qualities to the companions of the Prophet, and to the tabiins, as if they would never err or never make a mistake. Strange.
That is why I have a new found immense respect to our brothers and sisters belonging to the Ahmadi sect, who painstakingly scrutinize narrations, without accepting them wholesale.
Edit: Forgive me if this sounds more of an argument. I am merely bringing light the Hadith mentioned in the discourse.