I couldn't find a narration with the word أحفظنا but I did find one with the word أقرؤنا,
كتاب التفسير في ((صحيح البخاري)) سورة البقرة، باب قوله (ما ننسخ من آية) ص ٩٩ ج ٣
حدثنا عمرو بن علي حدثنا يحيى حدثنا سفيان عن حبيب عن سعيد بن جبير عن ابن عباس قال قال عمر رضي الله عنه أقرؤنا أبي وأقضانا علي وإنا لندع من قول أبي وذاك أن أبيا يقول لا أدع شيئا سمعته من رسول الله صلى الله عليه وسلم وقد قال الله تعالى ما ننسخ من آية أو ننسها
Another version is narrated by Ibn Abbaas narrating from Umar.
Of interest is that elaborators of Hadeeth commented that this narration proves three things: That Ubayy did not accept the abrogation doctrine, that the Sahaaba were not in agreement about it and that 2:106 proves it.
A related post (in the widow verses thread) about the issue of leaving out something that the Prophet (PBUH) said, this time attributed to Uthman (RA). It would be great if we can get authenticate the narration and get the Arabic text.
In his book
, Burton dedicates pages 56-80, more than 10% of the entire book, to this abrogation claim. He asserts that this is the prime example used in several classical books on "the Abrogating and the Abrogated," and also used during the time of the Sahaba and early Muslims, to show the abrogation of a ruling without elimination of the verse containing it (the abrogation mode our thesis is against). He contends that he proved the claim to be false, and was content with that as a proof of the fallacy of this abrogation mode (quite a bit of a leap).
He has however, provided a remarkably elaborate historical view of this early abrogation claim, citing a number of relevant hadiths, showing conflicting opinions of the major Sahaba, and pointing out the labored efforts to arrive at an abrogation conclusion. I can't ascertain the accuracy of his references (perhaps they should be checked against Zaid's analysis of the same abrogation claim since he also rejects it). However, there are two notable observations one gets from reading this part of the book (assuming the facts are verifiable as correct and unbiased):1.
There are irreconcilable disagreements between the major Sahaba that are crisply demonstrated in this case. This shows that quoting an opinion of a single Sahabi in the context of proving something is quite vulnerable to pick-and-choose biases.2.
On pages 58 and 59, the author mentions Othman Ibn Affan's (may God be pleased with him) insistence on including in the Othmani copies of the Quran all the verses that the Prophet (PBUH) kept reciting even when other Sahabis claimed their rules were superseded, and also insisted in maintaining the order of verses in the Quran as the Prophet recited them even if an earlier verse was claimed to have abrogated a later verse (like the present abrogation claim). Othman has always been my hero because he focussed on the most important mission of all which is preserving the Quran. May God reward him for that on behalf of all of us.