What is the ruling when the Imam mobilizes people for war?

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When the Imam calls upon a group of people to mobilize for war (*istinfar*), it becomes obligatory upon them to join him in the mobilization. This obligation is derived from the Divine Admonition: O you who have believed, what is it with you that when you are told, 'Go forth in the cause of Allah,' you become heavy on the earth? (Quran 9:38) and the subsequent verse. The Prophet, peace and blessings be upon him, confirmed this with the directive: When you are summoned to mobilize, then mobilize.