Imam Al-Mujtaba (as)...
Imam Al-Mujtaba (as), explaining the different situation said that their success in the Siffin war was due to their religious leaning, sincerity and devotion, while the loss and their defeat in the war during his time was due to the absence of these very qualities. In other words, now they wanted personal and worldly benefits. Now they were not fighting with the religious zeal and true spirit, but rather for their own worldly gain.
Later, the grandson of the Holy Prophet (saws) referred to the two wars which had a profound effect on their destiny, i.e. the Siffin war, and the Nahrwan war. So many other wars had also been fought but in these two wars they had suffered very heavy losses which could not be recompensed. They had not been able to overcome the negative effects of these wars, and particularly those of the Nahrwan war, as they were full of rage due to the feeling of enmity and the spirit of revenge.
Therefore, Imam Al-Mujtaba (as) considers them belonging to two different groups: one who was shedding tears on the loved ones who lost their life in the long and bloody Siffin war. This group was relatively better and, therefore, was ready to fight a defensive war along with Imam Al-Mujtaba (as). The other group either belonged to the very 'Khawarij' group or had sympathy with it.
Though they were involved in the conspiracy to assassinate Hazrat ‘Ali (as), yet they wanted to take revenge from the worthy son of the leader of faithful Imam ‘Ali (as) as well. About the rest, the Imam (as) said that they had kept away from war. Sheikh Mufid is the first historian who, taking advantage of the above quoted words of Imam Al-Mujtaba (as), has clearly divided his army into different groups. The later historians have also written about this grouping.
Briefly, the following five groups constituted the army of the noble Imam. Shia A particular class of people, devoted to Imam Hasan (as) and his illustrious father, having a special identity based on faith, thought, intellect and mystic knowledge. These people consider caliphate as the right of the household of the Holy Prophet (saws) ('Ahlul Bayt') from the very beginning, and obedience to them as obligatory.
There was no doubt about their asceticism, piety, faith, sincerity, honesty and devotion to 'Ahlul Bayt' (as) among these were well known and prominent personalities and the of the Holy Prophet (saws) as well.