In the Musnad of Imam Ahmad (835) it is stated that Ali (RA) considered Abu Bakr to be the best of this Ummah after its Prophet. How do the Shia respond to it?
as salam alaikum
mere single reports from Musnad Ahmad cannot be validated according to Shia view. Also, according to the most accurate opinion any single report (khabar al-wahid) with no external evidences cannot be used to establish doctrinal principles or historical facts.
With prayers for your success.