English Translation: Page 70
Then after the distress, He sent down security for you. Slumber
overtook a party of you, while another party was thinking about themselves (as
how to save their ownselves, ignoring the others and the Prophet
صلى الله عليه
وسلم) and thought wrongly of Allâh - the thought of
ignorance. They said, "Have we any part in the affair?" Say (O
Muhammad صلى الله
عليه وسلم): "Indeed the
affair belongs wholly to Allâh." They hide within themselves what they
dare not reveal to you, saying: "If we had anything to do with the affair,
none of us would have been killed here." Say: "Even if you had
remained in your homes, those for whom death was decreed would certainly have
gone forth to the place of their death," but that Allâh might test what is
in your breasts; and to purify 
that which was in your hearts (sins), and Allâh is All-Knower of what is in
Those of you who turned back on the day the two hosts met (i.e. the
battle of Uhud), it was Shaitân
(Satan) who caused them to backslide
(run away from the battlefield) because of some (sins) they had earned. But Allâh,
indeed, has forgiven them. Surely, Allâh is Oft-Forgiving, Most Forbearing.
O you who believe! Be not like those who disbelieve (hypocrites) and
who say to their brethren when they travel through the earth or go out to fight:
"If they had stayed with us, they would not have died or been killed,"
so that Allâh may make it a cause of regret in their hearts. It is Allâh that
gives life and causes death. And Allâh is All-Seer of what you do.
And if you are killed or die in the Way of Allâh, forgiveness and
mercy from Allâh are far better than all that they amass (of worldly wealths).
(V.3:154) The Arabic word yumahhis has three meanings: (1) To test, (2)
To purify, (3) To get rid of (TafsirAl-Qurtubi ).