And there did Allah replace the emotion of sorrow and grief which was caused by fear of the unpredictable outcome by peace of mind and sense of security thus inducing your eyes to take themselves to slumber. He sent down from the floor of the vault of heaven rain - water to free you people from foreign matter as well as from moral and spiritual pollution and from the incitement of evil instigated by AL-Shaytan (Satan) and by those with characteristics befitting Him, and to do your hearts good and set your feet firm.