INVITING WARRIORS AND PROCURING EXPENSES OF WAR
The Prophet was aware to some extent of the capability and experience of the enemy and was sure that besides necessitating spiritual capital (viz. faith in Allah and fighting for the sake of Allah), victory in this battle also depended on a big army. Keeping this fact in view he sent men to Makkah as well as to the areas adjoining Madina to invite Muslims to fight in the path of Allah and also to ask well-to-do Muslims to provide for the expenses of war by making payment of zakat.
Soon after the proclamation made by the Prophet, 30,000 persons declared their readiness to participate in the battle and gathered in the camping ground of Madina (Thaniyya tul Wida'). The expenses of war were provided by collecting zakat. Out of these 30,000 men, 10,000 were mounted soldiers and the remaining 20,000 were infantry-men. Later the Prophet ordered that every tribe should choose a standard for itself.[1]
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1 Tabaqat, vol. II, page 166.
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Taken From : The Message by Ayatullah Ja'far Subhani
source : sibtayn
