When Abu Bakr bin Quhafa was using his force to get his pledge of allegiance, He even had ordered his close commander Khalid bin Waleed to slay Imam Ali (as) if he had refused to pledge the allegiance to Abu Bakr. We may find these traditions in Shi'a books but in Sunni corpus only remenants are left in which it is evident how sunni scholarship used to filter out these type of narrations and as a result of which much of the record of those events was lost. Whatever is left is only tip of that iceberg. Muhaditheen used to hide the narrations when they sense that it is going against their beliefs.
Pakistani Salafi scholar Muhammad Yahya Gondlawi even dared to say in his book that one example of a Narration being fabricated is that
" Any narration upon which there is agreement of scholars that it must be hidden like Ali being Wasi and Caliph after Prophet (pbuh) "
Dha'eef and Mawd'u Riwayaat - Gondlawi // Page 61 // Edn. Al Kitab International Delhi.
Now coming to main topic !
Abu Bakr Al-Khallal (Died 311 AH) narrates :
أَخْبَرَنِي مُحَمَّدُ بْنُ عَلِيٍّ، قَالَ: ثَنَا الْأَثْرَمُ، قَالَ: سَمِعْتُ أَبَا عَبْدِ اللَّهِ، وَذُكِرَ لَهُ حَدِيثُ عُقَيْلٍ، عَنِ الزُّهْرِيِّ، عَنْ عُرْوَةَ، عَنْ عَائِشَةَ، عَنِ النَّبِيِّ صَلَّى اللهُ عَلَيْهِ وَسَلَّمَ فِي عَلِيٍّ، وَالْعَبَّاسِ، وَعَقِيلٍ، عَنِ الزُّهْرِيِّ، أَنَّ أَبَا بَكْرٍ أَمَّرَ خَالِدًا فِي عَلِيٍّ، فَقَالَ أَبُو عَبْدِ اللَّهِ: كَيْفَ؟ فَلَمْ يَعْرِفْهَا، فَقَالَ: مَا يُعْجِبُنِي أَنْ تُكْتَبَ هَذِهِ الْأَحَادِيثُ
Al-Atharm narrates that he heard Ahmad bin Hanbal when a narration from Aqeel frln Zuhri from Urwah frl Aisha from Prophet (pbuh) about Ali and Abbas and another narration from Aqeel from Zuhri that Abu Bakr has ordered Khalid regarding Ali.
Ahmad said : How is it possible that i don't know it. Then he said : I dislike to write down these Narrations.
Now the real question is what was the order given by Abu Bakr to Khalid which Ahmad bin Hanbal dislike to write down ?
Imam Sam'ani (Died 542 AH) writes in his book about a Reliable narrator of Sahihian - Ebaad bin Yaqub Al-Rujani like this :
قلت روى عنه جماعة من مشاهير الأئمة مثل أبى عبد الله محمد بن إسماعيل البخاري لأنه لم يكن داعية إلى هواه، وروى عنه حديث أبى بكر رضي الله عنه أنه قال:
لا يفعل خالد ما أمر به، سألت الشريف عمر بن إبراهيم الحسيني بالكوفة عن معنى هذا الأثر فقال: كان أمر خالد بن الوليد أن يقتل عليا ثم ندم بعد ذلك فنهى عن ذلك
I say : A group from among the famous Imams have narrated from him like Abu Abdillah Muhammad bin Ismael Al-Bukhari because he wasn't caller to his innovation and from him has been narrated the Tradition of Abu Bakr who said to Khalid not to do what i had ordered you to do.
Sam'ani says that i asked Sharif Umar bin Ibrahim Al-Hussaini in Kufa about the meaning of this narration. He replied : Abh Bakr had ordered Khalid to kill Ali Ibn Abi Talib (as), He then repented and ordered him not to do that.