Re: Battle of Safeen and Camel.
^ also, it has been said that the verse "This day I have perfected your religion..." was the last in one respect as no verse regarding halal/haram or shariah rulings was revealed after it - hence the deen had been completed in that regard, even though the verse "And fear the day when ye shall be brought back to God..." was chronologically the last (okay, just noticed that one of the above links already said something to this effect).
and may i add my thanks for your earlier reply, Ibn Sadique... very well put
i think it was khalifa Umar ibn Abdul Aziz who when asked about the fighting that took place in the time of Ali/Muawiya replied: "Allah saved us from entering our swords into the fighting, so let us likewise withhold our tongues from entering into the matter" (or words to that effect)