The Qur'an qualifies ‘the believers’ with patience...
So, if there be of you a hundred patient (steadfast men), they will overcome two hundred; and if there be of you a thousand, they will overcome two thousand by the leave of Allah; and Allah is with the patient (steadfast ones).”*** The purpose of ‘weakness’, mentioned in the verse, is weakness in Faith and spiritualities, because the troops of Islam had not become decreased from the point of physical strength and number when they defeated.
In this verse, and the verse before it, the Qur'an points to three spiritual aspects which are the factors of victory, the absence of which is a preparation for defeat; they are: patience, Faith, and vigilance. Thus, the main function in victory is by the leave and Will of Allah, else, in the Battle of Hunayn, where there were so many fighters Muslims defeated and ran away. The verse says: “Now Allah has lightened it for you, and He knows that there is weakness in you.
So, If there be of you a hundred patient (steadfast men), they will overcome two hundred; and if there be of you a thousand, they will overcome two thousand by the leave of Allah...” However, the patients are loved by Allah and they are in His refuge.
You desire the transitory world, while Allah desires (for you) the Hereafter; and Allah is the Mighty the Wise.”*** Allah has allowed no prophet to take the members of the enemy as captives and to keep them as pledge in order to take money from them, or hold them under obligation and let them go; unless that he exaggerates in killing the heathens an destroying them so that it becomes as a warning to others and that he gains authority.