45. Allah did not approve of the exemption which the Prophet (peace be upon him) had granted to the hypocrites who had put forward lame excuses. Though he knew it well that they were inventing false excuses, he gave them leave to stay behind because of his inherent kindness. But Allah warned him that such a leniency was not well placed as he gave them an opportunity of hiding their hypocrisy. Had they remained behind without getting an exemption, the false profession of their faith would have been exposed.
46. This verse shows clearly that the conflict between Islam and kufr is the criterion to distinguish between a true believer and a hypocrite. The one who supports Islam in this conflict with the whole of his heart and expends all of his energies and resources in order to make it victorious and does not hesitate in the least to make any sacrifices for this purpose, is a true believer. On the contrary, the one who hesitates to support Islam in this conflict and refrains from making sacrifices in its way, when he confronts the threat of the victory of kufr, is a hypocrite, for such an attitude is itself a proof of the fact that there is no faith in his heart.
47. Allah held them back for He did not like that they should join Jihad unwillingly without any sincere intention for it. As they had no mind to make sacrifices to exalt the cause of Islam, and, therefore, would have taken part in it half-heartedly to escape the taunts of the Muslims or to create mischief. This would have resulted in a greater evil, as has been stated explicitly in the next verse 48.