There was never any compulsion that all Muslims should join the army.
There was never any compulsion that all Muslims should join the army. At any rate, there was not a semblance of an army during the Prophet’s time.
The propensity of an Arab’s mind, in those days, to readily incline towards all sorts of expeditions and warfare for the sake of Ghanima (spoils of war in the form of slave boys and girls in addition to the usual booty) was only too well-known to the Caliphs .[^6] The Caliphs cleverly gave a religious colour to the adventure for the sake of infusing in their soldiers that zeal and disregard for life which is so essential for winning a war.
When Abu Bakr became the first Caliph , he was confronted with complicated issues of religion as well as governance. In all such cases, he referred people to Umar for finding a solution. So frequent was this done that people started asking Abu Bakr:“ Are you the Caliph or Umar is the Caliph?” Umar was also seen to reverse several decisions made by Abu Bakr. However, invariably both Abu Bakr and Umar considered Ali (a.s.) as the final authority.
They repeated the tradition in which the Prophet (S) had declared:“ Among you the best Judge is Ali .” Umar often confessed:“ But for Ali, Umar would have perished.” Many such instances are compiled in a book under the title “ Qadhaya (judgments of) Ameerul Mo’minin .” Whenever Muslims met privately or in congregation after prayers, there was open and fierce discussions about the ignorance so often exhibited publicly by the Caliph and his inability to find solutions to even the simplest questions that arose.
They compared the Caliph ’s incompetence to the ease with which Imam Ali (a.s.) solved the most difficult issues. People in every congregation, recounted the various traditions of the Prophet (S) extolling Imam Ali’s supremacy over all the other Muslims in knowledge, virtue, valor and nobility.
They also recounted the various occasions when the Prophet (S) nominated Imam Ali (a.s.) as his successor, and how, unfortunately, inept and ignorant persons deprived him of his rightful and deserving place. The discussions became more serious in the month of Ramadan when large gatherings assembled in mosques after breaking the mandatory fast. Umar found large groups openly expressing their dissatisfaction with the capabilities of the Caliph.
In order to prevent such critical discussions, Umar ordered that instead of indulging in discussions, people should spend their time in prayers.